16 changed files with 528 additions and 463 deletions
--- a/Main.lean
+++ b/Main.lean
@ -4,6 +4,7 @@ import Lean.Environment
 import Pantograph.Version
 import Pantograph.Library
 import Pantograph
 import Repl
 -- Main IO functions
 open Pantograph
--- a/Pantograph.lean
+++ b/Pantograph.lean
@ -1,211 +1,8 @@
 import Lean.Data.HashMap
 import Pantograph.Compile
 import Pantograph.Condensed
 import Pantograph.Environment
 import Pantograph.Goal
 import Pantograph.Library
 import Pantograph.Protocol
 import Pantograph.Serial
-
+import Pantograph.Version
 namespace Pantograph
 structure Context where
  imports: List String
 /-- Stores state of the REPL -/
 structure State where
  options: Protocol.Options := {}
  nextId: Nat := 0
  goalStates: Lean.HashMap Nat GoalState := Lean.HashMap.empty
 /-- Main state monad for executing commands -/
 abbrev MainM := ReaderT Context (StateT State Lean.CoreM)
 -- HACK: For some reason writing `CommandM α := MainM (Except ... α)` disables
 -- certain monadic features in `MainM`
 abbrev CR α := Except Protocol.InteractionError α
 def execute (command: Protocol.Command): MainM Lean.Json := do
  let run { α β: Type } [Lean.FromJson α] [Lean.ToJson β] (comm: α → MainM (CR β)): MainM Lean.Json :=
    match Lean.fromJson? command.payload with
    | .ok args => do
      match (← comm args) with
      | .ok result =>  return Lean.toJson result
      | .error ierror => return Lean.toJson ierror
    | .error error => return Lean.toJson $ errorCommand s!"Unable to parse json: {error}"
  match command.cmd with
  | "reset"         => run reset
  | "stat"          => run stat
  | "expr.echo"     => run expr_echo
  | "env.catalog"   => run env_catalog
  | "env.inspect"   => run env_inspect
  | "env.add"       => run env_add
  | "options.set"   => run options_set
  | "options.print" => run options_print
  | "goal.start"    => run goal_start
  | "goal.tactic"   => run goal_tactic
  | "goal.continue" => run goal_continue
  | "goal.delete"   => run goal_delete
  | "goal.print"    => run goal_print
  | "compile.unit"  => run compile_unit
  | cmd =>
    let error: Protocol.InteractionError :=
      errorCommand s!"Unknown command {cmd}"
    return Lean.toJson error
  where
  errorCommand := errorI "command"
  errorIndex := errorI "index"
  -- Command Functions
  reset (_: Protocol.Reset): MainM (CR Protocol.StatResult) := do
    let state ← get
    let nGoals := state.goalStates.size
    set { state with nextId := 0, goalStates := Lean.HashMap.empty }
    return .ok { nGoals }
  stat (_: Protocol.Stat): MainM (CR Protocol.StatResult) := do
    let state ← get
    let nGoals := state.goalStates.size
    return .ok { nGoals }
  env_catalog (args: Protocol.EnvCatalog): MainM (CR Protocol.EnvCatalogResult) := do
    let result ← Environment.catalog args
    return .ok result
  env_inspect (args: Protocol.EnvInspect): MainM (CR Protocol.EnvInspectResult) := do
    let state ← get
    Environment.inspect args state.options
  env_add (args: Protocol.EnvAdd): MainM (CR Protocol.EnvAddResult) := do
    Environment.addDecl args
  expr_echo (args: Protocol.ExprEcho): MainM (CR Protocol.ExprEchoResult) := do
    let state ← get
    exprEcho args.expr (expectedType? := args.type?) (levels := args.levels.getD #[]) (options := state.options)
  options_set (args: Protocol.OptionsSet): MainM (CR Protocol.OptionsSetResult) := do
    let state ← get
    let options := state.options
    set { state with
      options := {
        -- FIXME: This should be replaced with something more elegant
        printJsonPretty := args.printJsonPretty?.getD options.printJsonPretty,
        printExprPretty := args.printExprPretty?.getD options.printExprPretty,
        printExprAST := args.printExprAST?.getD options.printExprAST,
        printDependentMVars := args.printDependentMVars?.getD options.printDependentMVars,
        noRepeat := args.noRepeat?.getD options.noRepeat,
        printAuxDecls := args.printAuxDecls?.getD options.printAuxDecls,
        printImplementationDetailHyps := args.printImplementationDetailHyps?.getD options.printImplementationDetailHyps
      }
    }
    return .ok {  }
  options_print (_: Protocol.OptionsPrint): MainM (CR Protocol.Options) := do
    return .ok (← get).options
  goal_start (args: Protocol.GoalStart): MainM (CR Protocol.GoalStartResult) := do
    let state ← get
    let env ← Lean.MonadEnv.getEnv
    let expr?: Except _ GoalState ← runTermElabM (match args.expr, args.copyFrom with
      | .some expr, .none => goalStartExpr expr (args.levels.getD #[])
      | .none, .some copyFrom =>
        (match env.find? <| copyFrom.toName with
        | .none => return .error <| errorIndex s!"Symbol not found: {copyFrom}"
        | .some cInfo => return .ok (← GoalState.create cInfo.type))
      | _, _ =>
        return .error <| errorI "arguments" "Exactly one of {expr, copyFrom} must be supplied")
    match expr? with
    | .error error => return .error error
    | .ok goalState =>
      let stateId := state.nextId
      set { state with
        goalStates := state.goalStates.insert stateId goalState,
        nextId := state.nextId + 1
      }
      return .ok { stateId, root := goalState.root.name.toString }
  goal_tactic (args: Protocol.GoalTactic): MainM (CR Protocol.GoalTacticResult) := do
    let state ← get
    match state.goalStates.find? args.stateId with
    | .none => return .error $ errorIndex s!"Invalid state index {args.stateId}"
    | .some goalState => do
      let nextGoalState?: Except _ GoalState ←
        match args.tactic?, args.expr?, args.have?, args.calc?, args.conv?  with
        | .some tactic, .none, .none, .none, .none => do
          pure ( Except.ok (← goalTactic goalState args.goalId tactic))
        | .none, .some expr, .none, .none, .none => do
          pure ( Except.ok (← goalAssign goalState args.goalId expr))
        | .none, .none, .some type, .none, .none => do
          let binderName := args.binderName?.getD ""
          pure ( Except.ok (← goalState.tryHave args.goalId binderName type))
        | .none, .none, .none, .some pred, .none => do
          pure ( Except.ok (← goalCalc goalState args.goalId pred))
        | .none, .none, .none, .none, .some true => do
          pure ( Except.ok (← goalConv goalState args.goalId))
        | .none, .none, .none, .none, .some false => do
          pure ( Except.ok (← goalConvExit goalState))
        | _, _, _, _, _ => pure (Except.error <|
          errorI "arguments" "Exactly one of {tactic, expr, have, calc, conv} must be supplied")
      match nextGoalState? with
      | .error error => return .error error
      | .ok (.success nextGoalState) =>
        let nextStateId := state.nextId
        set { state with
          goalStates := state.goalStates.insert state.nextId nextGoalState,
          nextId := state.nextId + 1,
        }
        let goals ← nextGoalState.serializeGoals (parent := .some goalState) (options := state.options) |>.run'
        return .ok {
          nextStateId? := .some nextStateId,
          goals? := .some goals,
        }
      | .ok (.parseError message) =>
        return .ok { parseError? := .some message }
      | .ok (.indexError goalId) =>
        return .error $ errorIndex s!"Invalid goal id index {goalId}"
      | .ok (.invalidAction message) =>
        return .error $ errorI "invalid" message
      | .ok (.failure messages) =>
        return .ok { tacticErrors? := .some messages }
  goal_continue (args: Protocol.GoalContinue): MainM (CR Protocol.GoalContinueResult) := do
    let state ← get
    match state.goalStates.find? args.target with
    | .none => return .error $ errorIndex s!"Invalid state index {args.target}"
    | .some target => do
      let nextState? ← match args.branch?, args.goals? with
        | .some branchId, .none => do
          match state.goalStates.find? branchId with
          | .none => return .error $ errorIndex s!"Invalid state index {branchId}"
          | .some branch => pure $ target.continue branch
        | .none, .some goals =>
          pure $ goalResume target goals
        | _, _ => return .error <| errorI "arguments" "Exactly one of {branch, goals} must be supplied"
      match nextState? with
      | .error error => return .error <| errorI "structure" error
      | .ok nextGoalState =>
        let nextStateId := state.nextId
        set { state with
          goalStates := state.goalStates.insert nextStateId nextGoalState,
          nextId := state.nextId + 1
        }
        let goals ← goalSerialize nextGoalState (options := state.options)
        return .ok {
          nextStateId,
          goals,
        }
  goal_delete (args: Protocol.GoalDelete): MainM (CR Protocol.GoalDeleteResult) := do
    let state ← get
    let goalStates := args.stateIds.foldl (λ map id => map.erase id) state.goalStates
    set { state with goalStates }
    return .ok {}
  goal_print (args: Protocol.GoalPrint): MainM (CR Protocol.GoalPrintResult) := do
    let state ← get
    match state.goalStates.find? args.stateId with
    | .none => return .error $ errorIndex s!"Invalid state index {args.stateId}"
    | .some goalState => runMetaM <| do
      return .ok (← goalPrint goalState state.options)
  compile_unit (args: Protocol.CompileUnit): MainM (CR Protocol.CompileUnitResult) := do
    let module := args.module.toName
    try
      let steps ← Compile.processSource module
      let units? := if args.compilationUnits then
          .some $ steps.map λ step => (step.src.startPos.byteIdx, step.src.stopPos.byteIdx)
        else
          .none
      let invocations? ← if args.invocations then
          pure $ .some (← Compile.collectTacticsFromCompilation steps)
        else
          pure .none
      return .ok { units?, invocations? }
    catch e =>
      return .error $ errorI "compile" (← e.toMessageData.toString)
 end Pantograph
--- a/Pantograph/Goal.lean
+++ b/Pantograph/Goal.lean
@ -27,10 +27,11 @@ structure GoalState where
  parentMVar?: Option MVarId
  -- Existence of this field shows that we are currently in `conv` mode.
-  convMVar?: Option (MVarId × MVarId) := .none
+  -- (convRhs, goal, dormant)
  convMVar?: Option (MVarId × MVarId × List MVarId) := .none
  -- Previous RHS for calc, so we don't have to repeat it every time
  -- WARNING: If using `state with` outside of `calc`, this must be set to `.none`
-  calcPrevRhs?: Option Expr := .none
+  calcPrevRhs?: Option (MVarId × Expr) := .none
@[export pantograph_goal_state_create_m]
 protected def GoalState.create (expr: Expr): Elab.TermElabM GoalState := do
@ -96,6 +97,20 @@ protected def GoalState.focus (state: GoalState) (goalId: Nat): Option GoalState
    calcPrevRhs? := .none,
  }
 /-- Immediately bring all parent goals back into scope. Used in automatic mode -/
@[export pantograph_goal_state_immediate_resume_parent]
 protected def GoalState.immediateResume (state: GoalState) (parent: GoalState): GoalState :=
  -- Prune parents solved goals
  let mctx := state.mctx
  let parentGoals := parent.goals.filter $ λ goal => mctx.eAssignment.contains goal
  {
    state with
    savedState := {
      state.savedState with
      tactic := { goals := state.goals ++ parentGoals },
    },
  }
 /--
 Brings into scope a list of goals
 -/
@ -115,7 +130,6 @@ protected def GoalState.resume (state: GoalState) (goals: List MVarId): Except S
        term := state.savedState.term,
        tactic := { goals := unassigned },
      },
      calcPrevRhs? := .none,
    }
 /--
 Brings into scope all goals from `branch`
@ -147,24 +161,24 @@ protected def GoalState.parentExpr? (goalState: GoalState): Option Expr := do
  let (expr, _) := instantiateMVarsCore (mctx := goalState.mctx) (e := expr)
  return expr
@[export pantograph_goal_state_get_mvar_e_assignment]
-protected def GoalState.getMVarEAssignment (goalState: GoalState) (mvar: MVarId): Option Expr := do
+protected def GoalState.getMVarEAssignment (goalState: GoalState) (mvarId: MVarId): Option Expr := do
-  let expr ← goalState.mctx.eAssignment.find? mvar
+  let expr ← goalState.mctx.eAssignment.find? mvarId
  let (expr, _) := instantiateMVarsCore (mctx := goalState.mctx) (e := expr)
  return expr
 --- Tactic execution functions ---
-protected def GoalState.step (state: GoalState) (mvarId: MVarId) (tacticM: Elab.Tactic.TacticM Unit)
+protected def GoalState.step (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit)
  : Elab.TermElabM GoalState := do
-  unless (← getMCtx).decls.contains mvarId do
+  unless (← getMCtx).decls.contains goal do
-    throwError s!"MVarId is not in context: {mvarId.name}"
+    throwError s!"Goal is not in context: {goal.name}"
-  mvarId.checkNotAssigned `GoalState.step
+  goal.checkNotAssigned `GoalState.step
-  let (_, newGoals) ← tacticM { elaborator := .anonymous } |>.run { goals := [mvarId] }
+  let (_, newGoals) ← tacticM { elaborator := .anonymous } |>.run { goals := [goal] }
  let nextElabState ← MonadBacktrack.saveState
  return {
    state with
    savedState := { term := nextElabState, tactic := newGoals },
-    parentMVar? := .some mvarId,
+    parentMVar? := .some goal,
    calcPrevRhs? := .none,
  }
@ -176,25 +190,20 @@ inductive TacticResult where
  | failure (messages: Array String)
  -- Could not parse tactic
  | parseError (message: String)
  -- The goal index is out of bounds
  | indexError (goalId: Nat)
  -- The given action cannot be executed in the state
  | invalidAction (message: String)
 /-- Executes a `TacticM` monads on this `GoalState`, collecting the errors as necessary -/
-protected def GoalState.tryTacticM (state: GoalState) (goalId: Nat) (tacticM: Elab.Tactic.TacticM Unit):
+protected def GoalState.tryTacticM (state: GoalState) (goal: MVarId) (tacticM: Elab.Tactic.TacticM Unit):
      Elab.TermElabM TacticResult := do
  let mvarId ← match state.savedState.tactic.goals.get? goalId with
    | .some goal => pure $ goal
    | .none => return .indexError goalId
  try
-    let nextState ← state.step mvarId tacticM
+    let nextState ← state.step goal tacticM
    return .success nextState
  catch exception =>
    return .failure #[← exception.toMessageData.toString]
-/-- Execute a string tactic on given state -/
+/-- Execute a string tactic on given state. Restores TermElabM -/
-protected def GoalState.tryTactic (state: GoalState) (goalId: Nat) (tactic: String):
+protected def GoalState.tryTactic (state: GoalState) (goal: MVarId) (tactic: String):
    Elab.TermElabM TacticResult := do
  state.restoreElabM
  let tactic ← match Parser.runParserCategory
@ -204,9 +213,9 @@ protected def GoalState.tryTactic (state: GoalState) (goalId: Nat) (tactic: Stri
    (fileName := filename) with
    | .ok stx => pure $ stx
    | .error error => return .parseError error
-  state.tryTacticM goalId $ Elab.Tactic.evalTactic tactic
+  state.tryTacticM goal $ Elab.Tactic.evalTactic tactic
-protected def GoalState.tryAssign (state: GoalState) (goalId: Nat) (expr: String):
+protected def GoalState.tryAssign (state: GoalState) (goal: MVarId) (expr: String):
      Elab.TermElabM TacticResult := do
  state.restoreElabM
  let expr ← match Parser.runParserCategory
@ -216,11 +225,11 @@ protected def GoalState.tryAssign (state: GoalState) (goalId: Nat) (expr: String
    (fileName := filename) with
    | .ok syn => pure syn
    | .error error => return .parseError error
-  state.tryTacticM goalId $ Tactic.evalAssign expr
+  state.tryTacticM goal $ Tactic.evalAssign expr
 -- Specialized Tactics
-protected def GoalState.tryLet (state: GoalState) (goalId: Nat) (binderName: String) (type: String):
+protected def GoalState.tryLet (state: GoalState) (goal: MVarId) (binderName: String) (type: String):
      Elab.TermElabM TacticResult := do
  state.restoreElabM
  let type ← match Parser.runParserCategory
@ -230,17 +239,13 @@ protected def GoalState.tryLet (state: GoalState) (goalId: Nat) (binderName: Str
    (fileName := filename) with
    | .ok syn => pure syn
    | .error error => return .parseError error
-  state.tryTacticM goalId $ Tactic.evalLet binderName.toName type
+  state.tryTacticM goal $ Tactic.evalLet binderName.toName type
 /-- Enter conv tactic mode -/
-@[export pantograph_goal_state_conv_m]
+protected def GoalState.conv (state: GoalState) (goal: MVarId):
 protected def GoalState.conv (state: GoalState) (goalId: Nat):
      Elab.TermElabM TacticResult := do
  if state.convMVar?.isSome then
    return .invalidAction "Already in conv state"
  let goal ← match state.savedState.tactic.goals.get? goalId with
    | .some goal => pure goal
    | .none => return .indexError goalId
  goal.checkNotAssigned `GoalState.conv
  let tacticM :  Elab.Tactic.TacticM (Elab.Tactic.SavedState × MVarId) := do
    state.restoreTacticM goal
@ -253,11 +258,13 @@ protected def GoalState.conv (state: GoalState) (goalId: Nat):
    return (← MonadBacktrack.saveState, convMVar)
  try
    let (nextSavedState, convRhs) ← tacticM { elaborator := .anonymous } |>.run' state.savedState.tactic
    -- Other goals are now dormant
    let otherGoals := state.goals.filter $ λ g => g != goal
    return .success {
      root := state.root,
      savedState := nextSavedState
      parentMVar? := .some goal,
-      convMVar? := .some (convRhs, goal),
+      convMVar? := .some (convRhs, goal, otherGoals),
      calcPrevRhs? := .none
    }
  catch exception =>
@ -267,7 +274,7 @@ protected def GoalState.conv (state: GoalState) (goalId: Nat):
@[export pantograph_goal_state_conv_exit_m]
 protected def GoalState.convExit (state: GoalState):
      Elab.TermElabM TacticResult := do
-  let (convRhs, convGoal) ← match state.convMVar? with
+  let (convRhs, convGoal, _) ← match state.convMVar? with
    | .some mvar => pure mvar
    | .none => return .invalidAction "Not in conv state"
  let tacticM :  Elab.Tactic.TacticM Elab.Tactic.SavedState:= do
@ -300,21 +307,18 @@ protected def GoalState.convExit (state: GoalState):
  catch exception =>
    return .failure #[← exception.toMessageData.toString]
-protected def GoalState.calcPrevRhsOf? (state: GoalState) (goalId: Nat) :=
+protected def GoalState.calcPrevRhsOf? (state: GoalState) (goal: MVarId): Option Expr := do
-  if goalId == 1 then
+  let (mvarId, rhs) ← state.calcPrevRhs?
-    state.calcPrevRhs?
+  if mvarId == goal then
    .some rhs
  else
    .none
@[export pantograph_goal_state_try_calc_m]
-protected def GoalState.tryCalc (state: GoalState) (goalId: Nat) (pred: String):
+protected def GoalState.tryCalc (state: GoalState) (goal: MVarId) (pred: String):
      Elab.TermElabM TacticResult := do
  state.restoreElabM
  if state.convMVar?.isSome then
    return .invalidAction "Cannot initiate `calc` while in `conv` state"
  let goal ← match state.savedState.tactic.goals.get? goalId with
    | .some goal => pure goal
    | .none => return .indexError goalId
  let `(term|$pred) ← match Parser.runParserCategory
    (env := state.env)
    (catName := `term)
@ -323,9 +327,10 @@ protected def GoalState.tryCalc (state: GoalState) (goalId: Nat) (pred: String):
    | .ok syn => pure syn
    | .error error => return .parseError error
  goal.checkNotAssigned `GoalState.tryCalc
-  let calcPrevRhs? := state.calcPrevRhsOf? goalId
+  let calcPrevRhs? := state.calcPrevRhsOf? goal
-  let target ← instantiateMVars (← goal.getDecl).type
+  let decl ← goal.getDecl
-  let tag := (← goal.getDecl).userName
+  let target ← instantiateMVars decl.type
  let tag := decl.userName
  try
    goal.withContext do
@ -349,9 +354,8 @@ protected def GoalState.tryCalc (state: GoalState) (goalId: Nat) (pred: String):
      (userName := tag ++ `calc)
    let mvarBranch := proof.mvarId!
    let calcPrevRhs? := Option.some rhs
    let mut proofType ← Meta.inferType proof
-    let mut remainder := Option.none
+    let mut remainder? := Option.none
    -- The calc tactic either solves the main goal or leaves another relation.
    -- Replace the main goal, and save the new goal if necessary
@ -364,10 +368,11 @@ protected def GoalState.tryCalc (state: GoalState) (goalId: Nat) (pred: String):
      let lastStepGoal ← Meta.mkFreshExprSyntheticOpaqueMVar lastStep tag
      (proof, proofType) ← Elab.Term.mkCalcTrans proof proofType lastStepGoal lastStep
      unless ← Meta.isDefEq proofType target do throwFailed
-      remainder := .some lastStepGoal.mvarId!
+      remainder? := .some lastStepGoal.mvarId!
    goal.assign proof
-    let goals := [ mvarBranch ] ++ remainder.toList
+    let goals := [ mvarBranch ] ++ remainder?.toList
    let calcPrevRhs? := remainder?.map $ λ g => (g, rhs)
    return .success {
      root := state.root,
      savedState := {
@ -381,19 +386,19 @@ protected def GoalState.tryCalc (state: GoalState) (goalId: Nat) (pred: String):
    return .failure #[← exception.toMessageData.toString]
-protected def GoalState.tryMotivatedApply (state: GoalState) (goalId: Nat) (recursor: String):
+protected def GoalState.tryMotivatedApply (state: GoalState) (goal: MVarId) (recursor: String):
      Elab.TermElabM TacticResult := do
  state.restoreElabM
  let recursor ← match (← Compile.parseTermM recursor) with
    | .ok syn => pure syn
    | .error error => return .parseError error
-  state.tryTacticM goalId (tacticM := Tactic.evalMotivatedApply recursor)
+  state.tryTacticM goal (tacticM := Tactic.evalMotivatedApply recursor)
-protected def GoalState.tryNoConfuse (state: GoalState) (goalId: Nat) (eq: String):
+protected def GoalState.tryNoConfuse (state: GoalState) (goal: MVarId) (eq: String):
      Elab.TermElabM TacticResult := do
  state.restoreElabM
  let eq ← match (← Compile.parseTermM eq) with
    | .ok syn => pure syn
    | .error error => return .parseError error
-  state.tryTacticM goalId (tacticM := Tactic.evalNoConfuse eq)
+  state.tryTacticM goal (tacticM := Tactic.evalNoConfuse eq)
 end Pantograph
--- a/Pantograph/Library.lean
+++ b/Pantograph/Library.lean
@ -152,38 +152,38 @@ def goalPrint (state: GoalState) (options: @&Protocol.Options): CoreM Protocol.G
    }
@[export pantograph_goal_tactic_m]
-def goalTactic (state: GoalState) (goalId: Nat) (tactic: String): CoreM TacticResult :=
+def goalTactic (state: GoalState) (goal:  MVarId) (tactic: String): CoreM TacticResult :=
-  runTermElabM <| state.tryTactic goalId tactic
+  runTermElabM <| state.tryTactic goal tactic
@[export pantograph_goal_assign_m]
-def goalAssign (state: GoalState) (goalId: Nat) (expr: String): CoreM TacticResult :=
+def goalAssign (state: GoalState) (goal: MVarId) (expr: String): CoreM TacticResult :=
-  runTermElabM <| state.tryAssign goalId expr
+  runTermElabM <| state.tryAssign goal expr
@[export pantograph_goal_have_m]
-protected def GoalState.tryHave (state: GoalState) (goalId: Nat) (binderName: String) (type: String): CoreM TacticResult := do
+protected def GoalState.tryHave (state: GoalState) (goal: MVarId) (binderName: String) (type: String): CoreM TacticResult := do
  let type ← match (← Compile.parseTermM type) with
    | .ok syn => pure syn
    | .error error => return .parseError error
  runTermElabM do
    state.restoreElabM
-    state.tryTacticM goalId $ Tactic.evalHave binderName.toName type
+    state.tryTacticM goal $ Tactic.evalHave binderName.toName type
@[export pantograph_goal_try_define_m]
-protected def GoalState.tryDefine (state: GoalState) (goalId: Nat) (binderName: String) (expr: String): CoreM TacticResult := do
+protected def GoalState.tryDefine (state: GoalState) (goal: MVarId) (binderName: String) (expr: String): CoreM TacticResult := do
  let expr ← match (← Compile.parseTermM expr) with
    | .ok syn => pure syn
    | .error error => return .parseError error
  runTermElabM do
    state.restoreElabM
-    state.tryTacticM goalId (Tactic.evalDefine binderName.toName expr)
+    state.tryTacticM goal (Tactic.evalDefine binderName.toName expr)
@[export pantograph_goal_let_m]
-def goalLet (state: GoalState) (goalId: Nat) (binderName: String) (type: String): CoreM TacticResult :=
+def goalLet (state: GoalState) (goal: MVarId) (binderName: String) (type: String): CoreM TacticResult :=
-  runTermElabM <| state.tryLet goalId binderName type
+  runTermElabM <| state.tryLet goal binderName type
@[export pantograph_goal_conv_m]
-def goalConv (state: GoalState) (goalId: Nat): CoreM TacticResult :=
+def goalConv (state: GoalState) (goal: MVarId): CoreM TacticResult :=
-  runTermElabM <| state.conv goalId
+  runTermElabM <| state.conv goal
@[export pantograph_goal_conv_exit_m]
 def goalConvExit (state: GoalState): CoreM TacticResult :=
  runTermElabM <| state.convExit
@[export pantograph_goal_calc_m]
-def goalCalc (state: GoalState) (goalId: Nat) (pred: String): CoreM TacticResult :=
+def goalCalc (state: GoalState) (goal: MVarId) (pred: String): CoreM TacticResult :=
-  runTermElabM <| state.tryCalc goalId pred
+  runTermElabM <| state.tryCalc goal pred
 end Pantograph
--- a/Pantograph/Protocol.lean
+++ b/Pantograph/Protocol.lean
@ -27,6 +27,8 @@ structure Options where
  printAuxDecls: Bool      := false
  -- See `pp.implementationDetailHyps`
  printImplementationDetailHyps: Bool := false
  -- If this is set to `true`, goals will never go dormant, so you don't have to manage resumption
  automaticMode: Bool := false
  deriving Lean.ToJson
 abbrev OptionsT := ReaderT Options
@ -190,6 +192,7 @@ structure OptionsSet where
  noRepeat?: Option Bool
  printAuxDecls?: Option Bool
  printImplementationDetailHyps?: Option Bool
  automaticMode?: Option Bool
  deriving Lean.FromJson
 structure OptionsSetResult where
  deriving Lean.ToJson
--- a/Pantograph/Version.lean
+++ b/Pantograph/Version.lean
@ -1,6 +1,6 @@
 namespace Pantograph
@[export pantograph_version]
-def version := "0.2.17"
+def version := "0.2.18"
 end Pantograph
--- a/README.md
+++ b/README.md
@ -90,6 +90,10 @@ See `Pantograph/Protocol.lean` for a description of the parameters and return va
  only the values of definitions are printed.
 * `options.set { key: value, ... }`: Set one or more options (not Lean options; those
  have to be set via command line arguments.), for options, see `Pantograph/Protocol.lean`
  One particular option for interest for machine learning researchers is the automatic mode.
  `options.set { "automaticMode": true }`. This makes Pantograph act like
  LeanDojo, with no resumption necessary to manage your goals.
 * `options.print`: Display the current set of options
 * `goal.start {["name": <name>], ["expr": <expr>], ["levels": [<levels>]], ["copyFrom": <symbol>]}`:
  Start a new proof from a given expression or symbol
--- a/Repl.lean
+++ b/Repl.lean
@ -0,0 +1,220 @@
 import Lean.Data.HashMap
 import Pantograph
 namespace Pantograph
 structure Context where
  imports: List String
 /-- Stores state of the REPL -/
 structure State where
  options: Protocol.Options := {}
  nextId: Nat := 0
  goalStates: Lean.HashMap Nat GoalState := Lean.HashMap.empty
 /-- Main state monad for executing commands -/
 abbrev MainM := ReaderT Context (StateT State Lean.CoreM)
 -- HACK: For some reason writing `CommandM α := MainM (Except ... α)` disables
 -- certain monadic features in `MainM`
 abbrev CR α := Except Protocol.InteractionError α
 def runMetaInMainM { α } (metaM: Lean.MetaM α): MainM α :=
  metaM.run'
 def runTermElabInMainM { α } (termElabM: Lean.Elab.TermElabM α) : MainM α :=
  termElabM.run' (ctx := Condensed.elabContext) |>.run'
 def execute (command: Protocol.Command): MainM Lean.Json := do
  let run { α β: Type } [Lean.FromJson α] [Lean.ToJson β] (comm: α → MainM (CR β)): MainM Lean.Json :=
    match Lean.fromJson? command.payload with
    | .ok args => do
      match (← comm args) with
      | .ok result =>  return Lean.toJson result
      | .error ierror => return Lean.toJson ierror
    | .error error => return Lean.toJson $ errorCommand s!"Unable to parse json: {error}"
  match command.cmd with
  | "reset"         => run reset
  | "stat"          => run stat
  | "expr.echo"     => run expr_echo
  | "env.catalog"   => run env_catalog
  | "env.inspect"   => run env_inspect
  | "env.add"       => run env_add
  | "options.set"   => run options_set
  | "options.print" => run options_print
  | "goal.start"    => run goal_start
  | "goal.tactic"   => run goal_tactic
  | "goal.continue" => run goal_continue
  | "goal.delete"   => run goal_delete
  | "goal.print"    => run goal_print
  | "compile.unit"  => run compile_unit
  | cmd =>
    let error: Protocol.InteractionError :=
      errorCommand s!"Unknown command {cmd}"
    return Lean.toJson error
  where
  errorCommand := errorI "command"
  errorIndex := errorI "index"
  -- Command Functions
  reset (_: Protocol.Reset): MainM (CR Protocol.StatResult) := do
    let state ← get
    let nGoals := state.goalStates.size
    set { state with nextId := 0, goalStates := Lean.HashMap.empty }
    return .ok { nGoals }
  stat (_: Protocol.Stat): MainM (CR Protocol.StatResult) := do
    let state ← get
    let nGoals := state.goalStates.size
    return .ok { nGoals }
  env_catalog (args: Protocol.EnvCatalog): MainM (CR Protocol.EnvCatalogResult) := do
    let result ← Environment.catalog args
    return .ok result
  env_inspect (args: Protocol.EnvInspect): MainM (CR Protocol.EnvInspectResult) := do
    let state ← get
    Environment.inspect args state.options
  env_add (args: Protocol.EnvAdd): MainM (CR Protocol.EnvAddResult) := do
    Environment.addDecl args
  expr_echo (args: Protocol.ExprEcho): MainM (CR Protocol.ExprEchoResult) := do
    let state ← get
    exprEcho args.expr (expectedType? := args.type?) (levels := args.levels.getD #[]) (options := state.options)
  options_set (args: Protocol.OptionsSet): MainM (CR Protocol.OptionsSetResult) := do
    let state ← get
    let options := state.options
    set { state with
      options := {
        -- FIXME: This should be replaced with something more elegant
        printJsonPretty := args.printJsonPretty?.getD options.printJsonPretty,
        printExprPretty := args.printExprPretty?.getD options.printExprPretty,
        printExprAST := args.printExprAST?.getD options.printExprAST,
        printDependentMVars := args.printDependentMVars?.getD options.printDependentMVars,
        noRepeat := args.noRepeat?.getD options.noRepeat,
        printAuxDecls := args.printAuxDecls?.getD options.printAuxDecls,
        printImplementationDetailHyps := args.printImplementationDetailHyps?.getD options.printImplementationDetailHyps
        automaticMode := args.automaticMode?.getD options.automaticMode,
      }
    }
    return .ok {  }
  options_print (_: Protocol.OptionsPrint): MainM (CR Protocol.Options) := do
    return .ok (← get).options
  goal_start (args: Protocol.GoalStart): MainM (CR Protocol.GoalStartResult) := do
    let state ← get
    let env ← Lean.MonadEnv.getEnv
    let expr?: Except _ GoalState ← runTermElabInMainM (match args.expr, args.copyFrom with
      | .some expr, .none => goalStartExpr expr (args.levels.getD #[])
      | .none, .some copyFrom =>
        (match env.find? <| copyFrom.toName with
        | .none => return .error <| errorIndex s!"Symbol not found: {copyFrom}"
        | .some cInfo => return .ok (← GoalState.create cInfo.type))
      | _, _ =>
        return .error <| errorI "arguments" "Exactly one of {expr, copyFrom} must be supplied")
    match expr? with
    | .error error => return .error error
    | .ok goalState =>
      let stateId := state.nextId
      set { state with
        goalStates := state.goalStates.insert stateId goalState,
        nextId := state.nextId + 1
      }
      return .ok { stateId, root := goalState.root.name.toString }
  goal_tactic (args: Protocol.GoalTactic): MainM (CR Protocol.GoalTacticResult) := do
    let state ← get
    let .some goalState := state.goalStates.find? args.stateId |
      return .error $ errorIndex s!"Invalid state index {args.stateId}"
    let .some goal := goalState.goals.get? args.goalId |
      return .error $ errorIndex s!"Invalid goal index {args.goalId}"
    let nextGoalState?: Except _ TacticResult ← runTermElabInMainM do
      match args.tactic?, args.expr?, args.have?, args.calc?, args.conv?  with
      | .some tactic, .none, .none, .none, .none => do
        pure <| Except.ok <| ← goalState.tryTactic goal tactic
      | .none, .some expr, .none, .none, .none => do
        pure <| Except.ok <| ← goalState.tryAssign goal expr
      | .none, .none, .some type, .none, .none => do
        let binderName := args.binderName?.getD ""
        pure <| Except.ok <| ← goalState.tryHave goal binderName type
      | .none, .none, .none, .some pred, .none => do
        pure <| Except.ok <| ← goalState.tryCalc goal pred
      | .none, .none, .none, .none, .some true => do
        pure <| Except.ok <| ← goalState.conv goal
      | .none, .none, .none, .none, .some false => do
        pure <| Except.ok <| ← goalState.convExit
      | _, _, _, _, _ =>
        let error := errorI "arguments" "Exactly one of {tactic, expr, have, calc, conv} must be supplied"
        pure $ Except.error $ error
    match nextGoalState? with
    | .error error => return .error error
    | .ok (.success nextGoalState) => do
      let nextGoalState ← match state.options.automaticMode, args.conv? with
        | true, .none => do
          let .ok result := nextGoalState.resume (nextGoalState.goals ++ goalState.goals) | throwError "Resuming known goals"
          pure result
        | true, .some true => pure nextGoalState
        | true, .some false => do
          let .some (_, _, dormantGoals) := goalState.convMVar? | throwError "If conv exit succeeded this should not fail"
          let .ok result := nextGoalState.resume (nextGoalState.goals ++ dormantGoals) | throwError "Resuming known goals"
          pure result
        | false, _ => pure nextGoalState
      let nextStateId := state.nextId
      set { state with
        goalStates := state.goalStates.insert state.nextId nextGoalState,
        nextId := state.nextId + 1,
      }
      let goals ← nextGoalState.serializeGoals (parent := .some goalState) (options := state.options) |>.run'
      return .ok {
        nextStateId? := .some nextStateId,
        goals? := .some goals,
      }
    | .ok (.parseError message) =>
      return .ok { parseError? := .some message }
    | .ok (.invalidAction message) =>
      return .error $ errorI "invalid" message
    | .ok (.failure messages) =>
      return .ok { tacticErrors? := .some messages }
  goal_continue (args: Protocol.GoalContinue): MainM (CR Protocol.GoalContinueResult) := do
    let state ← get
    let .some target := state.goalStates.find? args.target | return .error $ errorIndex s!"Invalid state index {args.target}"
    let nextState? ← match args.branch?, args.goals? with
      | .some branchId, .none => do
        match state.goalStates.find? branchId with
        | .none => return .error $ errorIndex s!"Invalid state index {branchId}"
        | .some branch => pure $ target.continue branch
      | .none, .some goals =>
        pure $ goalResume target goals
      | _, _ => return .error <| errorI "arguments" "Exactly one of {branch, goals} must be supplied"
    match nextState? with
    | .error error => return .error <| errorI "structure" error
    | .ok nextGoalState =>
      let nextStateId := state.nextId
      set { state with
        goalStates := state.goalStates.insert nextStateId nextGoalState,
        nextId := state.nextId + 1
      }
      let goals ← goalSerialize nextGoalState (options := state.options)
      return .ok {
        nextStateId,
        goals,
      }
  goal_delete (args: Protocol.GoalDelete): MainM (CR Protocol.GoalDeleteResult) := do
    let state ← get
    let goalStates := args.stateIds.foldl (λ map id => map.erase id) state.goalStates
    set { state with goalStates }
    return .ok {}
  goal_print (args: Protocol.GoalPrint): MainM (CR Protocol.GoalPrintResult) := do
    let state ← get
    let .some goalState := state.goalStates.find? args.stateId | return .error $ errorIndex s!"Invalid state index {args.stateId}"
    let result ← runMetaInMainM <| goalPrint goalState state.options
    return .ok result
  compile_unit (args: Protocol.CompileUnit): MainM (CR Protocol.CompileUnitResult) := do
    let module := args.module.toName
    try
      let steps ← Compile.processSource module
      let units? := if args.compilationUnits then
          .some $ steps.map λ step => (step.src.startPos.byteIdx, step.src.stopPos.byteIdx)
        else
          .none
      let invocations? ← if args.invocations then
          pure $ .some (← Compile.collectTacticsFromCompilation steps)
        else
          pure .none
      return .ok { units?, invocations? }
    catch e =>
      return .error $ errorI "compile" (← e.toMessageData.toString)
 end Pantograph
--- a/Test/Common.lean
+++ b/Test/Common.lean
@ -62,13 +62,15 @@ protected def Goal.devolatilize (goal: Goal): Goal :=
 end Condensed
 def GoalState.get! (state: GoalState) (i: Nat): MVarId := state.goals.get! i
 def GoalState.tacticOn (state: GoalState) (goalId: Nat) (tactic: String) := state.tryTactic (state.goals.get! goalId) tactic
 def TacticResult.toString : TacticResult → String
  | .success state => s!".success ({state.goals.length} goals)"
  | .failure messages =>
    let messages := "\n".intercalate messages.toList
    s!".failure {messages}"
  | .parseError error => s!".parseError {error}"
  | .indexError index => s!".indexError {index}"
  | .invalidAction error => s!".invalidAction {error}"
 namespace Test
--- a/Test/Integration.lean
+++ b/Test/Integration.lean
@ -2,39 +2,24 @@
 -/
 import LSpec
 import Pantograph
 import Repl
 import Test.Common
 namespace Pantograph.Test.Integration
 open Pantograph
-def subroutine_named_step (name cmd: String) (payload: List (String × Lean.Json))
+def step { α } [Lean.ToJson α] (cmd: String) (payload: List (String × Lean.Json))
-    (expected: Lean.Json): MainM LSpec.TestSeq := do
+    (expected: α) (name? : Option String := .none): MainM LSpec.TestSeq := do
-  let result ← execute { cmd := cmd, payload := Lean.Json.mkObj payload }
+  let payload := Lean.Json.mkObj payload
-  return LSpec.test name (toString result = toString expected)
+  let name := name?.getD s!"{cmd} {payload.compress}"
-def subroutine_step (cmd: String) (payload: List (String × Lean.Json))
+  let result ← execute { cmd, payload }
-    (expected: Lean.Json): MainM LSpec.TestSeq := subroutine_named_step cmd cmd payload expected
+  return LSpec.test name (toString result = toString (Lean.toJson expected))
-def subroutine_runner (steps: List (MainM LSpec.TestSeq)): IO LSpec.TestSeq := do
+abbrev Test := List (MainM LSpec.TestSeq)
  -- Setup the environment for execution
  let env ← Lean.importModules
    (imports := #[{module := Lean.Name.str .anonymous "Init", runtimeOnly := false }])
    (opts := {})
    (trustLevel := 1)
  let context: Context := {
    imports := ["Init"]
  }
  let coreContext: Lean.Core.Context ← createCoreContext #[]
  let commands: MainM LSpec.TestSeq :=
    steps.foldlM (λ suite step => do
      let result ← step
      return suite ++ result) LSpec.TestSeq.done
  try
    let coreM := commands.run context |>.run' {}
    return Prod.fst $ (← coreM.toIO coreContext { env := env })
  catch ex =>
    return LSpec.check s!"Uncaught IO exception: {ex.toString}" false
-def test_elab : IO LSpec.TestSeq :=
+def test_elab : Test :=
-  subroutine_runner [
+  [
-    subroutine_step "expr.echo"
+    step "expr.echo"
      [("expr", .str "λ {α : Sort (u + 1)} => List α"), ("levels", .arr #["u"])]
     (Lean.toJson ({
       type := { pp? := .some "{α : Type u} → Type u" },
@ -42,46 +27,33 @@ def test_elab : IO LSpec.TestSeq :=
     }: Protocol.ExprEchoResult)),
  ]
-def test_option_modify : IO LSpec.TestSeq :=
+def test_option_modify : Test :=
  let pp? := Option.some "∀ (n : Nat), n + 1 = n.succ"
  let sexp? := Option.some "(:forall n (:c Nat) ((:c Eq) (:c Nat) ((:c HAdd.hAdd) (:c Nat) (:c Nat) (:c Nat) ((:c instHAdd) (:c Nat) (:c instAddNat)) 0 ((:c OfNat.ofNat) (:c Nat) (:lit 1) ((:c instOfNatNat) (:lit 1)))) ((:c Nat.succ) 0)))"
  let module? := Option.some "Init.Data.Nat.Basic"
  let options: Protocol.Options := {}
-  subroutine_runner [
+  [
-    subroutine_step "env.inspect"
+    step "env.inspect" [("name", .str "Nat.add_one")]
-      [("name", .str "Nat.add_one")]
+     ({ type := { pp? }, module? }: Protocol.EnvInspectResult),
-     (Lean.toJson ({
+    step "options.set" [("printExprAST", .bool true)]
-       type := { pp? }, module? }:
+     ({ }: Protocol.OptionsSetResult),
-      Protocol.EnvInspectResult)),
+    step "env.inspect" [("name", .str "Nat.add_one")]
-    subroutine_step "options.set"
+     ({ type := { pp?, sexp? }, module? }: Protocol.EnvInspectResult),
-      [("printExprAST", .bool true)]
+    step "options.print" []
-     (Lean.toJson ({ }:
+     ({ options with printExprAST := true }: Protocol.Options),
      Protocol.OptionsSetResult)),
    subroutine_step "env.inspect"
      [("name", .str "Nat.add_one")]
     (Lean.toJson ({
       type := { pp?, sexp? }, module? }:
      Protocol.EnvInspectResult)),
    subroutine_step "options.print"
      []
     (Lean.toJson ({ options with printExprAST := true }:
      Protocol.Options))
  ]
-def test_malformed_command : IO LSpec.TestSeq :=
+def test_malformed_command : Test :=
  let invalid := "invalid"
-  subroutine_runner [
+  [
-    subroutine_named_step "Invalid command" invalid
+    step invalid [("name", .str "Nat.add_one")]
-      [("name", .str "Nat.add_one")]
+     ({ error := "command", desc := s!"Unknown command {invalid}" }: Protocol.InteractionError)
-     (Lean.toJson ({
+     (name? := .some "Invalid Command"),
-       error := "command", desc := s!"Unknown command {invalid}"}:
+    step "expr.echo" [(invalid, .str "Random garbage data")]
-      Protocol.InteractionError)),
+     ({ error := "command", desc := s!"Unable to parse json: Pantograph.Protocol.ExprEcho.expr: String expected" }:
-    subroutine_named_step "JSON Deserialization" "expr.echo"
+      Protocol.InteractionError)
-      [(invalid, .str "Random garbage data")]
+    (name? := .some "JSON Deserialization")
     (Lean.toJson ({
       error := "command", desc := s!"Unable to parse json: Pantograph.Protocol.ExprEcho.expr: String expected"}:
      Protocol.InteractionError))
  ]
-def test_tactic : IO LSpec.TestSeq :=
+def test_tactic : Test :=
  let goal1: Protocol.Goal := {
    name := "_uniq.11",
    target := { pp? := .some "∀ (q : Prop), x ∨ q → q ∨ x" },
@ -95,77 +67,123 @@ def test_tactic : IO LSpec.TestSeq :=
      { name := "_uniq.16", userName := "y", type? := .some { pp? := .some "Prop" }}
    ],
  }
-  subroutine_runner [
+  [
-    subroutine_step "goal.start"
+    step "goal.start" [("expr", .str "∀ (p q: Prop), p ∨ q → q ∨ p")]
-      [("expr", .str "∀ (p q: Prop), p ∨ q → q ∨ p")]
+     ({ stateId := 0, root := "_uniq.9" }: Protocol.GoalStartResult),
-     (Lean.toJson ({stateId := 0, root := "_uniq.9"}:
+    step "goal.tactic" [("stateId", .num 0), ("goalId", .num 0), ("tactic", .str "intro x")]
-      Protocol.GoalStartResult)),
+     ({ nextStateId? := .some 1, goals? := #[goal1], }: Protocol.GoalTacticResult),
-    subroutine_step "goal.tactic"
+    step "goal.print" [("stateId", .num 1)]
-      [("stateId", .num 0), ("goalId", .num 0), ("tactic", .str "intro x")]
+     ({ parent? := .some { pp? := .some "fun x => ?m.12 x" }, }: Protocol.GoalPrintResult),
-     (Lean.toJson ({
+    step "goal.tactic" [("stateId", .num 1), ("goalId", .num 0), ("tactic", .str "intro y")]
-       nextStateId? := .some 1,
+     ({ nextStateId? := .some 2, goals? := #[goal2], }: Protocol.GoalTacticResult),
-       goals? := #[goal1],
+  ]
-     }:
+def test_automatic_mode (automatic: Bool): Test :=
-      Protocol.GoalTacticResult)),
+  let varsPQ := #[
-    subroutine_step "goal.print"
+    { name := "_uniq.10", userName := "p", type? := .some { pp? := .some "Prop" }},
-      [("stateId", .num 1)]
+    { name := "_uniq.13", userName := "q", type? := .some { pp? := .some "Prop" }}
-     (Lean.toJson ({
+  ]
-       parent? := .some { pp? := .some "fun x => ?m.12 x" },
+  let goal1: Protocol.Goal := {
-     }:
+    name := "_uniq.17",
-      Protocol.GoalPrintResult)),
+    target := { pp? := .some "q ∨ p" },
-    subroutine_step "goal.tactic"
+    vars := varsPQ ++ #[
-      [("stateId", .num 1), ("goalId", .num 0), ("tactic", .str "intro y")]
+      { name := "_uniq.16", userName := "h", type? := .some { pp? := .some "p ∨ q" }}
-     (Lean.toJson ({
+    ],
-       nextStateId? := .some 2,
+  }
-       goals? := #[goal2],
+  let goal2l: Protocol.Goal := {
-     }:
+    name := "_uniq.59",
-      Protocol.GoalTacticResult))
+    userName? := .some "inl",
    target := { pp? := .some "q ∨ p" },
    vars := varsPQ ++ #[
      { name := "_uniq.47", userName := "h✝", type? := .some { pp? := .some "p" }, isInaccessible := true}
    ],
  }
  let goal2r: Protocol.Goal := {
    name := "_uniq.72",
    userName? := .some "inr",
    target := { pp? := .some "q ∨ p" },
    vars := varsPQ ++ #[
      { name := "_uniq.60", userName := "h✝", type? := .some { pp? := .some "q" }, isInaccessible := true}
    ],
  }
  let goal3l: Protocol.Goal := {
    name := "_uniq.78",
    userName? := .some "inl.h",
    target := { pp? := .some "p" },
    vars := varsPQ ++ #[
      { name := "_uniq.47", userName := "h✝", type? := .some { pp? := .some "p" }, isInaccessible := true}
    ],
  }
  [
    step "options.set" [("automaticMode", .bool automatic)]
     ({}: Protocol.OptionsSetResult),
    step "goal.start" [("expr", .str "∀ (p q: Prop), p ∨ q → q ∨ p")]
     ({ stateId := 0, root := "_uniq.9" }: Protocol.GoalStartResult),
    step "goal.tactic" [("stateId", .num 0), ("goalId", .num 0), ("tactic", .str "intro p q h")]
     ({ nextStateId? := .some 1, goals? := #[goal1], }: Protocol.GoalTacticResult),
    step "goal.tactic" [("stateId", .num 1), ("goalId", .num 0), ("tactic", .str "cases h")]
     ({ nextStateId? := .some 2, goals? := #[goal2l, goal2r], }: Protocol.GoalTacticResult),
    let goals? := if automatic then #[goal3l, goal2r] else #[goal3l]
    step "goal.tactic" [("stateId", .num 2), ("goalId", .num 0), ("tactic", .str "apply Or.inr")]
     ({ nextStateId? := .some 3, goals?, }: Protocol.GoalTacticResult),
  ]
-def test_env_add_inspect : IO LSpec.TestSeq :=
+def test_env_add_inspect : Test :=
  let name1 := "Pantograph.mystery"
  let name2 := "Pantograph.mystery2"
-  subroutine_runner [
+  [
-    subroutine_step "env.add"
+    step "env.add"
      [
        ("name", .str name1),
        ("type", .str "Prop → Prop → Prop"),
        ("value", .str "λ (a b: Prop) => Or a b"),
        ("isTheorem", .bool false)
      ]
-     (Lean.toJson ({}: Protocol.EnvAddResult)),
+     ({}: Protocol.EnvAddResult),
-    subroutine_step "env.inspect"
+    step "env.inspect" [("name", .str name1)]
-      [("name", .str name1)]
+     ({
     (Lean.toJson ({
       value? := .some { pp? := .some "fun a b => a ∨ b" },
       type := { pp? := .some "Prop → Prop → Prop" },
     }:
-      Protocol.EnvInspectResult)),
+      Protocol.EnvInspectResult),
-    subroutine_step "env.add"
+    step "env.add"
      [
        ("name", .str name2),
        ("type", .str "Nat → Int"),
        ("value", .str "λ (a: Nat) => a + 1"),
        ("isTheorem", .bool false)
      ]
-     (Lean.toJson ({}: Protocol.EnvAddResult)),
+     ({}: Protocol.EnvAddResult),
-    subroutine_step "env.inspect"
+    step "env.inspect" [("name", .str name2)]
-      [("name", .str name2)]
+     ({
     (Lean.toJson ({
       value? := .some { pp? := .some "fun a => ↑a + 1" },
       type := { pp? := .some "Nat → Int" },
     }:
-      Protocol.EnvInspectResult))
+      Protocol.EnvInspectResult)
  ]
-def suite: List (String × IO LSpec.TestSeq) :=
+def runTest (env: Lean.Environment) (steps: Test): IO LSpec.TestSeq := do
-  [
+  -- Setup the environment for execution
-    ("Elab", test_elab),
+  let context: Context := {
-    ("Option modify", test_option_modify),
+    imports := ["Init"]
  }
  let commands: MainM LSpec.TestSeq :=
    steps.foldlM (λ suite step => do
      let result ← step
      return suite ++ result) LSpec.TestSeq.done
  runCoreMSeq env <| commands.run context |>.run' {}
 def suite (env : Lean.Environment): List (String × IO LSpec.TestSeq) :=
  let tests := [
    ("expr.echo", test_elab),
    ("options.set options.print", test_option_modify),
    ("Malformed command", test_malformed_command),
    ("Tactic", test_tactic),
    ("Manual Mode", test_automatic_mode false),
    ("Automatic Mode", test_automatic_mode true),
    ("env.add env.inspect", test_env_add_inspect),
  ]
  tests.map (fun (name, test) => (name, runTest env test))
 end Pantograph.Test.Integration
--- a/Test/Main.lean
+++ b/Test/Main.lean
@ -44,7 +44,7 @@ def main (args: List String) := do
  let suites: List (String × List (String × IO LSpec.TestSeq)) := [
    ("Environment", Environment.suite),
-    ("Integration", Integration.suite),
+    ("Integration", Integration.suite env_default),
    ("Library", Library.suite env_default),
    ("Metavar", Metavar.suite env_default),
    ("Proofs", Proofs.suite env_default),
--- a/Test/Metavar.lean
+++ b/Test/Metavar.lean
@ -83,7 +83,7 @@ def test_m_couple: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := "apply Nat.le_trans") with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := "apply Nat.le_trans") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -92,7 +92,7 @@ def test_m_couple: TestM Unit := do
    #[.some "2 ≤ ?m", .some "?m ≤ 5", .some "Nat"])
  addTest $ LSpec.test "(1 root)" state1.rootExpr?.isNone
  -- Set m to 3
-  let state2 ← match ← state1.tryTactic (goalId := 2) (tactic := "exact 3") with
+  let state2 ← match ← state1.tacticOn (goalId := 2) (tactic := "exact 3") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -115,7 +115,7 @@ def test_m_couple_simp: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := "apply Nat.le_trans") with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := "apply Nat.le_trans") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -126,7 +126,7 @@ def test_m_couple_simp: TestM Unit := do
  addTest $ LSpec.check "(metavariables)" (serializedState1.map (·.target.dependentMVars?.get!) =
    #[#["_uniq.38"], #["_uniq.38"], #[]])
-  let state2 ← match ← state1.tryTactic (goalId := 2) (tactic := "exact 2") with
+  let state2 ← match ← state1.tacticOn (goalId := 2) (tactic := "exact 2") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -140,7 +140,7 @@ def test_m_couple_simp: TestM Unit := do
  addTest $ LSpec.check "exact 2" ((← state1b.serializeGoals (options := ← read)).map (·.target.pp?) =
    #[.some "2 ≤ 2", .some "2 ≤ 5"])
  addTest $ LSpec.test "(2 root)" state1b.rootExpr?.isNone
-  let state3 ← match ← state1b.tryTactic (goalId := 0) (tactic := "simp") with
+  let state3 ← match ← state1b.tacticOn (goalId := 0) (tactic := "simp") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -150,7 +150,7 @@ def test_m_couple_simp: TestM Unit := do
      addTest $ assertUnreachable $ msg
      return ()
    | .ok state => pure state
-  let state5 ← match ← state4.tryTactic (goalId := 0) (tactic := "simp") with
+  let state5 ← match ← state4.tacticOn (goalId := 0) (tactic := "simp") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -177,7 +177,7 @@ def test_proposition_generation: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := "apply PSigma.mk") with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := "apply PSigma.mk") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -191,7 +191,7 @@ def test_proposition_generation: TestM Unit := do
    addTest $ LSpec.test "(1 reference)" (goal1.target.sexp? = .some s!"(:mv {goal2.name})")
  addTest $ LSpec.test "(1 root)" state1.rootExpr?.isNone
-  let state2 ← match ← state1.tryAssign (goalId := 0) (expr := "λ (x: Nat) => _") with
+  let state2 ← match ← state1.tryAssign (state1.get! 0) (expr := "λ (x: Nat) => _") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -201,7 +201,7 @@ def test_proposition_generation: TestM Unit := do
  addTest $ LSpec.test "(2 root)" state2.rootExpr?.isNone
  let assign := "Eq.refl x"
-  let state3 ← match ← state2.tryAssign (goalId := 0) (expr := assign) with
+  let state3 ← match ← state2.tryAssign (state2.get! 0) (expr := assign) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -220,7 +220,7 @@ def test_partial_continuation: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := "apply Nat.le_trans") with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := "apply Nat.le_trans") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -228,7 +228,7 @@ def test_partial_continuation: TestM Unit := do
  addTest $ LSpec.check "apply Nat.le_trans" ((← state1.serializeGoals (options := ← read)).map (·.target.pp?) =
    #[.some "2 ≤ ?m", .some "?m ≤ 5", .some "Nat"])
-  let state2 ← match ← state1.tryTactic (goalId := 2) (tactic := "apply Nat.succ") with
+  let state2 ← match ← state1.tacticOn (goalId := 2) (tactic := "apply Nat.succ") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
--- a/Test/Proofs.lean
+++ b/Test/Proofs.lean
@ -91,7 +91,7 @@ def test_identity: TestM Unit := do
      return ()
  let tactic := "intro p h"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn 0 tactic with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -118,7 +118,7 @@ def test_nat_add_comm (manual: Bool): TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := "intro n m") with
+  let state1 ← match ← state0.tacticOn 0 "intro n m" with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -126,13 +126,13 @@ def test_nat_add_comm (manual: Bool): TestM Unit := do
  addTest $ LSpec.check "intro n m" ((← state1.serializeGoals (options := ← read)).map (·.devolatilize) =
    #[buildGoal [("n", "Nat"), ("m", "Nat")] "n + m = m + n"])
-  match ← state1.tryTactic (goalId := 0) (tactic := "assumption") with
+  match ← state1.tacticOn 0 "assumption" with
  | .failure #[message] =>
    addTest $ LSpec.check "assumption" (message = "tactic 'assumption' failed\nn m : Nat\n⊢ n + m = m + n")
  | other => do
    addTest $ assertUnreachable $ other.toString
-  let state2 ← match ← state1.tryTactic (goalId := 0) (tactic := "rw [Nat.add_comm]") with
+  let state2 ← match ← state1.tacticOn 0 "rw [Nat.add_comm]" with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -150,14 +150,14 @@ def test_delta_variable: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := "intro n") with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := "intro n") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
      return ()
  addTest $ LSpec.check "intro n" ((← state1.serializeGoals (parent := state0) options).map (·.devolatilize) =
    #[buildGoalSelective [("n", .some "Nat")] "∀ (b : Nat), n + b = b + n"])
-  let state2 ← match ← state1.tryTactic (goalId := 0) (tactic := "intro m") with
+  let state2 ← match ← state1.tacticOn (goalId := 0) (tactic := "intro m") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -189,14 +189,14 @@ def test_arith: TestM Unit := do
      return ()
  let tactic := "intros"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
      return ()
  addTest $ LSpec.check tactic (state1.goals.length = 1)
  addTest $ LSpec.test "(1 root)" state1.rootExpr?.isNone
-  let state2 ← match ← state1.tryTactic (goalId := 0) (tactic := "simp [Nat.add_assoc, Nat.add_comm, Nat.add_left_comm, Nat.mul_comm, Nat.mul_assoc, Nat.mul_left_comm] at *") with
+  let state2 ← match ← state1.tacticOn (goalId := 0) (tactic := "simp [Nat.add_assoc, Nat.add_comm, Nat.add_left_comm, Nat.mul_comm, Nat.mul_assoc, Nat.mul_left_comm] at *") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -204,7 +204,7 @@ def test_arith: TestM Unit := do
  addTest $ LSpec.check "simp ..." (state2.goals.length = 1)
  addTest $ LSpec.check "(2 root)" state2.rootExpr?.isNone
  let tactic := "assumption"
-  let state3 ← match ← state2.tryTactic (goalId := 0) (tactic := tactic) with
+  let state3 ← match ← state2.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -239,7 +239,7 @@ def test_or_comm: TestM Unit := do
  addTest $ LSpec.check "(0 root)" state0.rootExpr?.isNone
  let tactic := "intro p q h"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -265,7 +265,7 @@ def test_or_comm: TestM Unit := do
    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!) (sanitize := false)
  addTest $ LSpec.test "(1 parent)" (state1parent == s!"(:lambda p (:sort 0) (:lambda q (:sort 0) (:lambda h ((:c Or) 1 0) (:subst (:mv {state1g0}) 2 1 0))))")
  let tactic := "cases h"
-  let state2 ← match ← state1.tryTactic (goalId := 0) (tactic := tactic) with
+  let state2 ← match ← state1.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -289,7 +289,7 @@ def test_or_comm: TestM Unit := do
  addTest $ LSpec.test "(2 parent)" (state2parent ==
    s!"((:c Or.casesOn) (:fv {fvP}) (:fv {fvQ}) {motive} (:fv {fvH}) {caseL} {caseR} {conduit})")
-  let state3_1 ← match ← state2.tryTactic (goalId := 0) (tactic := "apply Or.inr") with
+  let state3_1 ← match ← state2.tacticOn (goalId := 0) (tactic := "apply Or.inr") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -298,7 +298,7 @@ def test_or_comm: TestM Unit := do
    serializeExpressionSexp (← instantiateAll state3_1.parentExpr?.get!) (sanitize := false)
  addTest $ LSpec.test "(3_1 parent)" (state3_1parent == s!"((:c Or.inr) (:fv {fvQ}) (:fv {fvP}) (:mv _uniq.91))")
  addTest $ LSpec.check "· apply Or.inr" (state3_1.goals.length = 1)
-  let state4_1 ← match ← state3_1.tryTactic (goalId := 0) (tactic := "assumption") with
+  let state4_1 ← match ← state3_1.tacticOn (goalId := 0) (tactic := "assumption") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -307,13 +307,13 @@ def test_or_comm: TestM Unit := do
  let state4_1parent ← instantiateAll state4_1.parentExpr?.get!
  addTest $ LSpec.test "(4_1 parent)" state4_1parent.isFVar
  addTest $ LSpec.check "(4_1 root)" state4_1.rootExpr?.isNone
-  let state3_2 ← match ← state2.tryTactic (goalId := 1) (tactic := "apply Or.inl") with
+  let state3_2 ← match ← state2.tacticOn (goalId := 1) (tactic := "apply Or.inl") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
      return ()
  addTest $ LSpec.check "· apply Or.inl" (state3_2.goals.length = 1)
-  let state4_2 ← match ← state3_2.tryTactic (goalId := 0) (tactic := "assumption") with
+  let state4_2 ← match ← state3_2.tacticOn (goalId := 0) (tactic := "assumption") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -327,13 +327,13 @@ def test_or_comm: TestM Unit := do
      return ()
    | .ok state => pure state
  addTest $ LSpec.test "(resume)" (state2b.goals == [state2.goals.get! 0])
-  let state3_1 ← match ← state2b.tryTactic (goalId := 0) (tactic := "apply Or.inr") with
+  let state3_1 ← match ← state2b.tacticOn (goalId := 0) (tactic := "apply Or.inr") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
      return ()
  addTest $ LSpec.check "· apply Or.inr" (state3_1.goals.length = 1)
-  let state4_1 ← match ← state3_1.tryTactic (goalId := 0) (tactic := "assumption") with
+  let state4_1 ← match ← state3_1.tacticOn (goalId := 0) (tactic := "assumption") with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -372,7 +372,7 @@ def test_conv: TestM Unit := do
      return ()
  let tactic := "intro a b c1 c2 h"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -380,7 +380,7 @@ def test_conv: TestM Unit := do
  addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.devolatilize) =
    #[interiorGoal [] "a + b + c1 = b + a + c2"])
-  let state2 ← match ← state1.conv (goalId := 0) with
+  let state2 ← match ← state1.conv (state1.get! 0) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -389,7 +389,7 @@ def test_conv: TestM Unit := do
    #[{ interiorGoal [] "a + b + c1 = b + a + c2" with isConversion := true }])
  let convTactic := "rhs"
-  let state3R ← match ← state2.tryTactic (goalId := 0) convTactic with
+  let state3R ← match ← state2.tacticOn (goalId := 0) convTactic with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -398,7 +398,7 @@ def test_conv: TestM Unit := do
    #[{ interiorGoal [] "b + a + c2" with isConversion := true }])
  let convTactic := "lhs"
-  let state3L ← match ← state2.tryTactic (goalId := 0) convTactic with
+  let state3L ← match ← state2.tacticOn (goalId := 0) convTactic with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -407,7 +407,7 @@ def test_conv: TestM Unit := do
    #[{ interiorGoal [] "a + b + c1" with isConversion := true }])
  let convTactic := "congr"
-  let state4 ← match ← state3L.tryTactic (goalId := 0) convTactic with
+  let state4 ← match ← state3L.tacticOn (goalId := 0) convTactic with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -419,7 +419,7 @@ def test_conv: TestM Unit := do
    ])
  let convTactic := "rw [Nat.add_comm]"
-  let state5_1 ← match ← state4.tryTactic (goalId := 0) convTactic with
+  let state5_1 ← match ← state4.tacticOn (goalId := 0) convTactic with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -428,7 +428,7 @@ def test_conv: TestM Unit := do
    #[{ interiorGoal [] "b + a" with isConversion := true, userName? := .some "a" }])
  let convTactic := "rfl"
-  let state6_1 ← match ← state5_1.tryTactic (goalId := 0) convTactic with
+  let state6_1 ← match ← state5_1.tacticOn (goalId := 0) convTactic with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -443,7 +443,7 @@ def test_conv: TestM Unit := do
      return ()
  let convTactic := "rfl"
-  let state6 ← match ← state4_1.tryTactic (goalId := 0) convTactic with
+  let state6 ← match ← state4_1.tacticOn (goalId := 0) convTactic with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -458,7 +458,7 @@ def test_conv: TestM Unit := do
      return ()
  let tactic := "exact h"
-  let stateF ← match ← state1_1.tryTactic (goalId := 0) (tactic := tactic) with
+  let stateF ← match ← state1_1.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -485,7 +485,7 @@ def test_calc: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
  let tactic := "intro a b c d h1 h2"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -493,7 +493,7 @@ def test_calc: TestM Unit := do
  addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.devolatilize) =
    #[interiorGoal [] "a + b = c + d"])
  let pred := "a + b = b + c"
-  let state2 ← match ← state1.tryCalc (goalId := 0) (pred := pred) with
+  let state2 ← match ← state1.tryCalc (state1.get! 0) (pred := pred) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -503,11 +503,11 @@ def test_calc: TestM Unit := do
      interiorGoal [] "a + b = b + c" (.some "calc"),
      interiorGoal [] "b + c = c + d"
    ])
-  addTest $ LSpec.test "(2.0 prev rhs)" (state2.calcPrevRhsOf? 0 |>.isNone)
+  addTest $ LSpec.test "(2.0 prev rhs)" (state2.calcPrevRhsOf? (state2.get! 0) |>.isNone)
-  addTest $ LSpec.test "(2.1 prev rhs)" (state2.calcPrevRhsOf? 1 |>.isSome)
+  addTest $ LSpec.test "(2.1 prev rhs)" (state2.calcPrevRhsOf? (state2.get! 1) |>.isSome)
  let tactic := "apply h1"
-  let state2m ← match ← state2.tryTactic (goalId := 0) (tactic := tactic) with
+  let state2m ← match ← state2.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -518,7 +518,7 @@ def test_calc: TestM Unit := do
      addTest $ expectationFailure "continue" e
      return ()
  let pred := "_ = c + d"
-  let state4 ← match ← state3.tryCalc (goalId := 0) (pred := pred) with
+  let state4 ← match ← state3.tryCalc (state3.get! 0) (pred := pred) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -527,9 +527,9 @@ def test_calc: TestM Unit := do
    #[
      interiorGoal [] "b + c = c + d" (.some "calc")
    ])
-  addTest $ LSpec.test "(4.0 prev rhs)" (state4.calcPrevRhsOf? 0 |>.isNone)
+  addTest $ LSpec.test "(4.0 prev rhs)" (state4.calcPrevRhsOf? (state4.get! 0) |>.isNone)
  let tactic := "apply h2"
-  let state4m ← match ← state4.tryTactic (goalId := 0) (tactic := tactic) with
+  let state4m ← match ← state4.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -549,7 +549,7 @@ def test_nat_zero_add: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
  let tactic := "intro n"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -557,7 +557,7 @@ def test_nat_zero_add: TestM Unit := do
  addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.devolatilize) =
    #[buildGoal [("n", "Nat")] "n + 0 = n"])
  let recursor := "@Nat.brecOn"
-  let state2 ← match ← state1.tryMotivatedApply (goalId := 0) (recursor := recursor) with
+  let state2 ← match ← state1.tryMotivatedApply (state1.get! 0) (recursor := recursor) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -571,7 +571,7 @@ def test_nat_zero_add: TestM Unit := do
    ])
  let tactic := "exact n"
-  let state3b ← match ← state2.tryTactic (goalId := 1) (tactic := tactic) with
+  let state3b ← match ← state2.tacticOn (goalId := 1) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -584,7 +584,7 @@ def test_nat_zero_add: TestM Unit := do
      addTest $ assertUnreachable e
      return ()
  let tactic := "exact (λ x => x + 0 = x)"
-  let state3c ← match ← state2b.tryTactic (goalId := 0) (tactic := tactic) with
+  let state3c ← match ← state2b.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -597,7 +597,7 @@ def test_nat_zero_add: TestM Unit := do
      addTest $ assertUnreachable e
      return ()
  let tactic := "intro t h"
-  let state3 ← match ← state2c.tryTactic (goalId := 0) (tactic := tactic) with
+  let state3 ← match ← state2c.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -606,7 +606,7 @@ def test_nat_zero_add: TestM Unit := do
    #[buildGoal [("n", "Nat"), ("t", "Nat"), ("h", "Nat.below t")] "t + 0 = t"])
  let tactic := "simp"
-  let state3d ← match ← state3.tryTactic (goalId := 0) (tactic := tactic) with
+  let state3d ← match ← state3.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -617,7 +617,7 @@ def test_nat_zero_add: TestM Unit := do
      addTest $ assertUnreachable e
      return ()
  let tactic := "rfl"
-  let stateF ← match ← state2d.tryTactic (goalId := 0) (tactic := tactic) with
+  let stateF ← match ← state2d.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -637,7 +637,7 @@ def test_nat_zero_add_alt: TestM Unit := do
      addTest $ assertUnreachable "Goal could not parse"
      return ()
  let tactic := "intro n"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -645,7 +645,7 @@ def test_nat_zero_add_alt: TestM Unit := do
  addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.devolatilize) =
    #[buildGoal [("n", "Nat")] "n + 0 = n"])
  let recursor := "@Nat.brecOn"
-  let state2 ← match ← state1.tryMotivatedApply (goalId := 0) (recursor := recursor) with
+  let state2 ← match ← state1.tryMotivatedApply (state1.get! 0) (recursor := recursor) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -660,7 +660,7 @@ def test_nat_zero_add_alt: TestM Unit := do
    ])
  let tactic := "intro x"
-  let state3m ← match ← state2.tryTactic (goalId := 0) (tactic := tactic) with
+  let state3m ← match ← state2.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -668,7 +668,7 @@ def test_nat_zero_add_alt: TestM Unit := do
  addTest $ LSpec.check tactic ((← state3m.serializeGoals (options := ← read)).map (·.devolatilize) =
    #[buildGoal [("n", "Nat"), ("x", "Nat")] "Prop" (.some "motive")])
  let tactic := "apply Eq"
-  let state3m2 ← match ← state3m.tryTactic (goalId := 0) (tactic := tactic) with
+  let state3m2 ← match ← state3m.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
--- a/Test/Tactic/Prograde.lean
+++ b/Test/Tactic/Prograde.lean
@ -55,7 +55,7 @@ def test_define_proof : TestT Elab.TermElabM Unit := do
  let rootExpr ← parseSentence "∀ (p q: Prop), p → ((p ∨ q) ∨ (p ∨ q))"
  let state0 ← GoalState.create rootExpr
  let tactic := "intro p q h"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -64,7 +64,7 @@ def test_define_proof : TestT Elab.TermElabM Unit := do
    #[buildGoal [("p", "Prop"), ("q", "Prop"), ("h", "p")] "(p ∨ q) ∨ p ∨ q"])
  let expr := "Or.inl (Or.inl h)"
-  let state2 ← match ← state1.tryAssign (goalId := 0) (expr := expr) with
+  let state2 ← match ← state1.tryAssign (state1.get! 0) (expr := expr) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -74,7 +74,7 @@ def test_define_proof : TestT Elab.TermElabM Unit := do
  let evalBind := "y"
  let evalExpr := "Or.inl h"
-  let state2 ← match ← state1.tryDefine (goalId := 0) (binderName := evalBind) (expr := evalExpr) with
+  let state2 ← match ← state1.tryDefine (state1.get! 0) (binderName := evalBind) (expr := evalExpr) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -94,7 +94,7 @@ def test_define_proof : TestT Elab.TermElabM Unit := do
  }])
  let expr := "Or.inl y"
-  let state3 ← match ← state2.tryAssign (goalId := 0) (expr := expr) with
+  let state3 ← match ← state2.tryAssign (state2.get! 0) (expr := expr) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -112,22 +112,22 @@ def fun_define_root_expr: ∀ (p: Prop), PProd (Nat → p) Unit → p := by
 def test_define_root_expr : TestT Elab.TermElabM Unit := do
  --let rootExpr ← parseSentence "Nat"
  --let state0 ← GoalState.create rootExpr
-  --let .success state1 ← state0.tryTactic (goalId := 0) "exact 5" | addTest $ assertUnreachable "exact 5"
+  --let .success state1 ← state0.tacticOn (goalId := 0) "exact 5" | addTest $ assertUnreachable "exact 5"
  --let .some rootExpr := state1.rootExpr? | addTest $ assertUnreachable "Root expr"
  --addTest $ LSpec.check "root" ((toString $ ← Meta.ppExpr rootExpr) = "5")
  let rootExpr ← parseSentence "∀ (p: Prop), PProd (Nat → p) Unit → p"
  let state0 ← GoalState.create rootExpr
  let tactic := "intro p x"
-  let .success state1 ← state0.tryTactic (goalId := 0) tactic | addTest $ assertUnreachable tactic
+  let .success state1 ← state0.tacticOn (goalId := 0) tactic | addTest $ assertUnreachable tactic
  let binderName := `binder
  let value := "x.fst"
  let expr ← state1.goals[0]!.withContext $ strToTermSyntax value
  let tacticM := Tactic.evalDefine binderName expr
-  let .success state2 ← state1.tryTacticM (goalId := 0) tacticM | addTest $ assertUnreachable s!"define {binderName} := {value}"
+  let .success state2 ← state1.tryTacticM (state1.get! 0) tacticM | addTest $ assertUnreachable s!"define {binderName} := {value}"
  let tactic := s!"apply {binderName}"
-  let .success state3 ← state2.tryTactic (goalId := 0) tactic | addTest $ assertUnreachable tactic
+  let .success state3 ← state2.tacticOn (goalId := 0) tactic | addTest $ assertUnreachable tactic
  let tactic := s!"exact 5"
-  let .success state4 ← state3.tryTactic (goalId := 0) tactic | addTest $ assertUnreachable tactic
+  let .success state4 ← state3.tacticOn (goalId := 0) tactic | addTest $ assertUnreachable tactic
  let .some rootExpr := state4.rootExpr? | addTest $ assertUnreachable "Root expr"
  addTest $ LSpec.check "root" ((toString $ ← Meta.ppExpr rootExpr) = "fun p x =>\n  let binder := x.fst;\n  binder 5")
@ -139,7 +139,7 @@ def test_have_proof : TestT Elab.TermElabM Unit := do
  let rootExpr ← parseSentence "∀ (p q: Prop), p → ((p ∨ q) ∨ (p ∨ q))"
  let state0 ← GoalState.create rootExpr
  let tactic := "intro p q h"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -148,7 +148,7 @@ def test_have_proof : TestT Elab.TermElabM Unit := do
    #[buildGoal [("p", "Prop"), ("q", "Prop"), ("h", "p")] "(p ∨ q) ∨ p ∨ q"])
  let expr := "Or.inl (Or.inl h)"
-  let state2 ← match ← state1.tryAssign (goalId := 0) (expr := expr) with
+  let state2 ← match ← state1.tryAssign (state1.get! 0) (expr := expr) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -158,7 +158,7 @@ def test_have_proof : TestT Elab.TermElabM Unit := do
  let haveBind := "y"
  let haveType := "p ∨ q"
-  let state2 ← match ← state1.tryHave (goalId := 0) (binderName := haveBind) (type := haveType) with
+  let state2 ← match ← state1.tryHave (state1.get! 0) (binderName := haveBind) (type := haveType) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -170,7 +170,7 @@ def test_have_proof : TestT Elab.TermElabM Unit := do
    ])
  let expr := "Or.inl h"
-  let state3 ← match ← state2.tryAssign (goalId := 0) (expr := expr) with
+  let state3 ← match ← state2.tryAssign (state2.get! 0) (expr := expr) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -184,7 +184,7 @@ def test_have_proof : TestT Elab.TermElabM Unit := do
      addTest $ assertUnreachable e
      return ()
  let expr := "Or.inl y"
-  let state4 ← match ← state2b.tryAssign (goalId := 0) (expr := expr) with
+  let state4 ← match ← state2b.tryAssign (state2b.get! 0) (expr := expr) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -199,7 +199,7 @@ def test_let (specialized: Bool): TestT Elab.TermElabM Unit := do
  let rootExpr ← parseSentence "∀ (p q: Prop), p → ((p ∨ q) ∨ (p ∨ q))"
  let state0 ← GoalState.create rootExpr
  let tactic := "intro a p h"
-  let state1 ← match ← state0.tryTactic (goalId := 0) (tactic := tactic) with
+  let state1 ← match ← state0.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -213,8 +213,8 @@ def test_let (specialized: Bool): TestT Elab.TermElabM Unit := do
  let letType := "Nat"
  let expr := s!"let b: {letType} := _; _"
  let result2 ← match specialized with
-    | true => state1.tryLet (goalId := 0) (binderName := "b") (type := letType)
+    | true => state1.tryLet (state1.get! 0) (binderName := "b") (type := letType)
-    | false => state1.tryAssign (goalId := 0) (expr := expr)
+    | false => state1.tryAssign (state1.get! 0) (expr := expr)
  let state2 ← match result2 with
    | .success state => pure state
    | other => do
@ -240,7 +240,7 @@ def test_let (specialized: Bool): TestT Elab.TermElabM Unit := do
    ])
  let tactic := "exact 1"
-  let state3 ← match ← state2.tryTactic (goalId := 0) (tactic := tactic) with
+  let state3 ← match ← state2.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
@ -266,14 +266,14 @@ def test_let (specialized: Bool): TestT Elab.TermElabM Unit := do
    ])
  let tactic := "exact h"
-  match ← state3r.tryTactic (goalId := 0) (tactic := tactic) with
+  match ← state3r.tacticOn (goalId := 0) (tactic := tactic) with
  | .failure #[message] =>
    addTest $ LSpec.check tactic  (message = s!"type mismatch\n  h\nhas type\n  a : Prop\nbut is expected to have type\n  {mainTarget} : Prop")
  | other => do
    addTest $ assertUnreachable $ other.toString
  let tactic := "exact Or.inl (Or.inl h)"
-  let state4 ← match ← state3r.tryTactic (goalId := 0) (tactic := tactic) with
+  let state4 ← match ← state3r.tacticOn (goalId := 0) (tactic := tactic) with
    | .success state => pure state
    | other => do
      addTest $ assertUnreachable $ other.toString
--- a/flake.nix
+++ b/flake.nix
@ -37,14 +37,25 @@
      };
      project = leanPkgs.buildLeanPackage {
        name = "Pantograph";
-        roots = [ "Main" "Pantograph" ];
+        roots = [ "Pantograph" ];
-        src = pkgs.lib.cleanSourceWith {
+        src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
          src = ./.;
          filter = path: type:
            !(pkgs.lib.hasInfix "/Test/" path) &&
            !(pkgs.lib.hasSuffix ".md" path) &&
-            !(pkgs.lib.hasSuffix "Makefile" path);
+            !(pkgs.lib.hasSuffix "Repl.lean" path);
-        };
+        });
      };
      repl = leanPkgs.buildLeanPackage {
        name = "Repl";
        roots = [ "Main" "Repl" ];
        deps = [ project ];
        src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
          src = ./.;
          filter = path: type:
            !(pkgs.lib.hasInfix "/Test/" path) &&
            !(pkgs.lib.hasSuffix ".md" path);
        });
      };
      test = leanPkgs.buildLeanPackage {
        name = "Test";
@ -52,18 +63,19 @@
        # root begins (e.g. `import Test.Environment` and not `import
        # Environment`) and thats where `lakefile.lean` resides.
        roots = [ "Test.Main" ];
-        deps = [ lspecLib project ];
+        deps = [ lspecLib repl ];
-        src = pkgs.lib.cleanSourceWith {
+        src = pkgs.lib.cleanSource (pkgs.lib.cleanSourceWith {
          src = ./.;
          filter = path: type:
            !(pkgs.lib.hasInfix "Pantograph" path);
-        };
+        });
      };
    in rec {
      packages = {
        inherit (leanPkgs) lean lean-all;
-        inherit (project) sharedLib executable;
+        inherit (project) sharedLib;
-        default = project.executable;
+        inherit (repl) executable;
        default = repl.executable;
      };
      legacyPackages = {
        inherit project leanPkgs;
--- a/lakefile.lean
+++ b/lakefile.lean
@ -4,11 +4,14 @@ open Lake DSL
 package pantograph
 lean_lib Pantograph {
  roots := #[`Pantograph]
  defaultFacets := #[LeanLib.sharedFacet]
 }
 lean_lib Repl {
 }
@[default_target]
-lean_exe pantograph {
+lean_exe repl {
  root := `Main
  -- Solves the native symbol not found problem
  supportInterpreter := true