Pantograph/Tactic/Congruence.lean

@@ -6,73 +6,80 @@ namespace Pantograph.Tactic
 
 def congruenceArg: Elab.Tactic.TacticM Unit := do
   let goal ← Elab.Tactic.getMainGoal
-  let .some (beta, _, _) := (← goal.getType).eq? | throwError "Goal is not an Eq"
-  -- Create the descendant goals
+  let .some (β, _, _) := (← goal.getType).eq? | throwError "Goal is not an Eq"
+  let userName := (← goal.getDecl).userName
 
   let nextGoals ← goal.withContext do
     let u ← Meta.mkFreshLevelMVar
-    let alpha ← Meta.mkFreshExprMVar (.some $ mkSort u) .natural .anonymous
-    let f ← Meta.mkFreshExprMVar (.some <| .forallE .anonymous alpha beta .default)
-      .synthetic (userName := goal.name ++ `f)
-    let a₁ ← Meta.mkFreshExprMVar (.some alpha)
-      .synthetic (userName := goal.name ++ `a₁)
-    let a₂ ← Meta.mkFreshExprMVar (.some alpha)
-      .synthetic (userName := goal.name ++ `a₂)
-    let h ← Meta.mkEq a₁ a₂
+    let α ← Meta.mkFreshExprMVar (.some $ mkSort u)
+      .natural (userName := userName ++ `α)
+    let f ← Meta.mkFreshExprMVar (.some <| .forallE .anonymous α β .default)
+      .synthetic (userName := userName ++ `f)
+    let a₁ ← Meta.mkFreshExprMVar (.some α)
+      .synthetic (userName := userName ++ `a₁)
+    let a₂ ← Meta.mkFreshExprMVar (.some α)
+      .synthetic (userName := userName ++ `a₂)
+    let h ← Meta.mkFreshExprMVar (.some $ ← Meta.mkEq a₁ a₂)
+      .synthetic (userName := userName ++ `h)
     let conduitType ← Meta.mkEq (← Meta.mkEq (.app f a₁) (.app f a₂)) (← goal.getType)
     let conduit ← Meta.mkFreshExprMVar conduitType
-      .synthetic (userName := goal.name ++ `conduit)
+      .synthetic (userName := userName ++ `conduit)
     goal.assign $ ← Meta.mkEqMP conduit (← Meta.mkCongrArg f h)
-    return [alpha, a₁, a₂, f,  h, conduit]
+    return [α, a₁, a₂, f,  h, conduit]
   Elab.Tactic.setGoals <| nextGoals.map (·.mvarId!)
 
 def congruenceFun: Elab.Tactic.TacticM Unit := do
   let goal ← Elab.Tactic.getMainGoal
-  let .some (beta, _, _) := (← goal.getType).eq? | throwError "Goal is not an Eq"
-  -- Create the descendant goals
+  let .some (β, _, _) := (← goal.getType).eq? | throwError "Goal is not an Eq"
+  let userName := (← goal.getDecl).userName
 
   let nextGoals ← goal.withContext do
     let u ← Meta.mkFreshLevelMVar
-    let alpha ← Meta.mkFreshExprMVar (.some $ mkSort u) .natural .anonymous
-    let fType := .forallE .anonymous alpha beta .default
+    let α ← Meta.mkFreshExprMVar (.some $ mkSort u)
+      .natural (userName := userName ++ `α)
+    let fType := .forallE .anonymous α β .default
     let f₁ ← Meta.mkFreshExprMVar (.some fType)
-      .synthetic (userName := goal.name ++ `f₁)
+      .synthetic (userName := userName ++ `f₁)
     let f₂ ← Meta.mkFreshExprMVar (.some fType)
-      .synthetic (userName := goal.name ++ `f₂)
-    let a ← Meta.mkFreshExprMVar (.some alpha)
-      .synthetic (userName := goal.name ++ `a)
-    let h ← Meta.mkEq f₁ f₂
+      .synthetic (userName := userName ++ `f₂)
+    let a ← Meta.mkFreshExprMVar (.some α)
+      .synthetic (userName := userName ++ `a)
+    let h ← Meta.mkFreshExprMVar (.some $ ← Meta.mkEq f₁ f₂)
+      .synthetic (userName := userName ++ `h)
     let conduitType ← Meta.mkEq (← Meta.mkEq (.app f₁ a) (.app f₂ a)) (← goal.getType)
     let conduit ← Meta.mkFreshExprMVar conduitType
-      .synthetic (userName := goal.name ++ `conduit)
+      .synthetic (userName := userName ++ `conduit)
     goal.assign $ ← Meta.mkEqMP conduit (← Meta.mkCongrFun h a)
-    return [alpha, f₁, f₂, h, a, conduit]
+    return [α, f₁, f₂, h, a, conduit]
   Elab.Tactic.setGoals <| nextGoals.map (·.mvarId!)
 
 def congruence: Elab.Tactic.TacticM Unit := do
   let goal ← Elab.Tactic.getMainGoal
-  let .some (beta, _, _) := (← goal.getType).eq? | throwError "Goal is not an Eq"
-  -- Create the descendant goals
+  let .some (β, _, _) := (← goal.getType).eq? | throwError "Goal is not an Eq"
+  let userName := (← goal.getDecl).userName
 
   let nextGoals ← goal.withContext do
     let u ← Meta.mkFreshLevelMVar
-    let alpha ← Meta.mkFreshExprMVar (.some $ mkSort u) .natural .anonymous
-    let fType := .forallE .anonymous alpha beta .default
+    let α ← Meta.mkFreshExprMVar (.some $ mkSort u)
+      .natural (userName := userName ++ `α)
+    let fType := .forallE .anonymous α β .default
     let f₁ ← Meta.mkFreshExprMVar (.some fType)
-      .synthetic (userName := goal.name ++ `f₁)
+      .synthetic (userName := userName ++ `f₁)
     let f₂ ← Meta.mkFreshExprMVar (.some fType)
-      .synthetic (userName := goal.name ++ `f₂)
-    let a₁ ← Meta.mkFreshExprMVar (.some alpha)
-      .synthetic (userName := goal.name ++ `a₁)
-    let a₂ ← Meta.mkFreshExprMVar (.some alpha)
-      .synthetic (userName := goal.name ++ `a₂)
-    let h₁ ← Meta.mkEq f₁ f₂
-    let h₂ ← Meta.mkEq a₁ a₂
+      .synthetic (userName := userName ++ `f₂)
+    let a₁ ← Meta.mkFreshExprMVar (.some α)
+      .synthetic (userName := userName ++ `a₁)
+    let a₂ ← Meta.mkFreshExprMVar (.some α)
+      .synthetic (userName := userName ++ `a₂)
+    let h₁ ← Meta.mkFreshExprMVar (.some $ ← Meta.mkEq f₁ f₂)
+      .synthetic (userName := userName ++ `h₁)
+    let h₂ ← Meta.mkFreshExprMVar (.some $ ← Meta.mkEq a₁ a₂)
+      .synthetic (userName := userName ++ `h₂)
     let conduitType ← Meta.mkEq (← Meta.mkEq (.app f₁ a₁) (.app f₂ a₂)) (← goal.getType)
     let conduit ← Meta.mkFreshExprMVar conduitType
-      .synthetic (userName := goal.name ++ `conduit)
+      .synthetic (userName := userName ++ `conduit)
     goal.assign $ ← Meta.mkEqMP conduit (← Meta.mkCongr h₁ h₂)
-    return [alpha, f₁, f₂, a₁, a₂, h₁, h₂, conduit]
+    return [α, f₁, f₂, a₁, a₂, h₁, h₂, conduit]
   Elab.Tactic.setGoals <| nextGoals.map (·.mvarId!)
 
 end Pantograph.Tactic

Test/Common.lean

@@ -27,6 +27,7 @@ def Goal.devolatilize (goal: Goal): Goal :=
     name := "",
   }
 
+deriving instance DecidableEq, Repr for Name
 deriving instance DecidableEq, Repr for Expression
 deriving instance DecidableEq, Repr for Variable
 deriving instance DecidableEq, Repr for Goal
@@ -65,9 +66,23 @@ def runTermElabMInMeta { α } (termElabM: Lean.Elab.TermElabM α): Lean.MetaM α
 
 def exprToStr (e: Expr): Lean.MetaM String := toString <$> Meta.ppExpr e
 
+def parseSentence (s: String): MetaM Expr := do
+  let recursor ← match Parser.runParserCategory
+    (env := ← MonadEnv.getEnv)
+    (catName := `term)
+    (input := s)
+    (fileName := filename) with
+    | .ok syn => pure syn
+    | .error error => throwError "Failed to parse: {error}"
+  runTermElabMInMeta $ Elab.Term.elabTerm (stx := recursor) .none
+
 def runTacticOnMVar (tacticM: Elab.Tactic.TacticM Unit) (goal: MVarId): Elab.TermElabM (List MVarId) := do
     let (_, newGoals) ← tacticM { elaborator := .anonymous } |>.run { goals := [goal] }
     return newGoals.goals
+def mvarUserNameAndType (mvarId: MVarId): MetaM (Name × String) := do
+  let name := (← mvarId.getDecl).userName
+  let t ← exprToStr (← mvarId.getType)
+  return (name, t)
 
 end Test
 

Test/Main.lean

@@ -49,6 +49,7 @@ def main (args: List String) := do
     ("Metavar", Metavar.suite env_default),
     ("Proofs", Proofs.suite env_default),
     ("Serial", Serial.suite env_default),
+    ("Tactic/Congruence", Tactic.Congruence.suite env_default),
     ("Tactic/Motivated Apply", Tactic.MotivatedApply.suite env_default),
     ("Tactic/No Confuse", Tactic.NoConfuse.suite env_default),
   ]

Test/Tactic.lean

@@ -1,2 +1,3 @@
+import Test.Tactic.Congruence
 import Test.Tactic.MotivatedApply
 import Test.Tactic.NoConfuse

Test/Tactic/Congruence.lean

@@ -0,0 +1,36 @@
+import LSpec
+import Lean
+import Test.Common
+
+open Lean
+open Pantograph
+
+namespace Pantograph.Test.Tactic.Congruence
+
+def test_congr_arg (env: Environment): IO LSpec.TestSeq :=
+  let expr := "λ (n m: Nat) (h: n = m) => n * n = m * m"
+  runMetaMSeq env do
+    let expr ← parseSentence expr
+    Meta.lambdaTelescope expr $ λ _ body => do
+      let mut tests := LSpec.TestSeq.done
+      let target ← Meta.mkFreshExprSyntheticOpaqueMVar body
+      let test ← runTermElabMInMeta do
+        let newGoals ← runTacticOnMVar Tactic.congruenceArg target.mvarId!
+        pure $ LSpec.check "goals" ((← newGoals.mapM (λ x => mvarUserNameAndType x)) =
+          [
+            (`α, "Sort ?u.70"),
+            (`a₁, "?α"),
+            (`a₂, "?α"),
+            (`f, "?α → Nat"),
+            (`h, "?a₁ = ?a₂"),
+            (`conduit, "(?f ?a₁ = ?f ?a₂) = (n * n = m * m)"),
+          ])
+      tests := tests ++ test
+      return tests
+
+def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
+  [
+    ("congrArg", test_congr_arg env),
+  ]
+
+end Pantograph.Test.Tactic.Congruence

Test/Tactic/NoConfuse.lean

@@ -92,9 +92,9 @@ def test_list (env: Environment): IO LSpec.TestSeq :=
 
 def suite (env: Environment): List (String × IO LSpec.TestSeq) :=
   [
-    ("nat", test_nat env),
-    ("nat_fail", test_nat_fail env),
-    ("list", test_list env),
+    ("Nat", test_nat env),
+    ("Nat fail", test_nat_fail env),
+    ("List", test_list env),
   ]
 
 end Pantograph.Test.Tactic.NoConfuse