diff --git a/Pantograph/Delate.lean b/Pantograph/Delate.lean
index 4b3bd51..38d8bda 100644
--- a/Pantograph/Delate.lean
+++ b/Pantograph/Delate.lean
@@ -264,25 +264,24 @@ def serializeName (name: Name) (sanitize: Bool := true): String :=
     if n.contains Lean.idBeginEscape then s!"{quote}{n}{quote}" else n
 
 /-- serialize a sort level. Expression is optimized to be compact e.g. `(+ u 2)` -/
-partial def serializeSortLevel (level: Level) (sanitize: Bool): String :=
+partial def serializeSortLevel (level: Level) : String :=
   let k := level.getOffset
   let u := level.getLevelOffset
   let u_str := match u with
     | .zero => "0"
     | .succ _ => panic! "getLevelOffset should not return .succ"
     | .max v w =>
-      let v := serializeSortLevel v sanitize
-      let w := serializeSortLevel w sanitize
+      let v := serializeSortLevel v
+      let w := serializeSortLevel w
       s!"(:max {v} {w})"
     | .imax v w =>
-      let v := serializeSortLevel v sanitize
-      let w := serializeSortLevel w sanitize
+      let v := serializeSortLevel v
+      let w := serializeSortLevel w
       s!"(:imax {v} {w})"
     | .param name =>
-      let name := serializeName name sanitize
       s!"{name}"
     | .mvar id =>
-      let name := serializeName id.name sanitize
+      let name := id.name
       s!"(:mv {name})"
   match k, u with
   | 0, _ => u_str
@@ -295,7 +294,7 @@ partial def serializeSortLevel (level: Level) (sanitize: Bool): String :=
 
 A `_` symbol in the AST indicates automatic deductions not present in the original expression.
 -/
-partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM String := do
+partial def serializeExpressionSexp (expr: Expr) : MetaM String := do
   self expr
   where
   delayedMVarToSexp (e: Expr): MetaM (Option String) := do
@@ -334,9 +333,10 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
         let name := mvarId.name
         pure s!"(:{pref} {name})"
     | .sort level =>
-      let level := serializeSortLevel level sanitize
+      let level := serializeSortLevel level
       pure s!"(:sort {level})"
     | .const declName _ =>
+      let declName := serializeName declName (sanitize := false)
       -- The universe level of the const expression is elided since it should be
       -- inferrable from surrounding expression
       pure s!"(:c {declName})"
@@ -369,7 +369,7 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
       -- is wrapped in a :lit sexp.
       let v' := match v with
         | .natVal val => toString val
-        | .strVal val => s!"\"{val}\""
+        | .strVal val => IR.EmitC.quoteString val
       pure s!"(:lit {v'})"
     | .mdata _ inner =>
       -- NOTE: Equivalent to expr itself, but mdata influences the prettyprinter
@@ -384,9 +384,9 @@ partial def serializeExpressionSexp (expr: Expr) (sanitize: Bool := true): MetaM
   -- Elides all unhygenic names
   binderInfoSexp : Lean.BinderInfo → String
     | .default => ""
-    | .implicit => " :implicit"
-    | .strictImplicit => " :strictImplicit"
-    | .instImplicit => " :instImplicit"
+    | .implicit => " :i"
+    | .strictImplicit => " :si"
+    | .instImplicit => " :ii"
 
 def serializeExpression (options: @&Protocol.Options) (e: Expr): MetaM Protocol.Expression := do
   let pp?: Option String ← match options.printExprPretty with
@@ -532,7 +532,7 @@ protected def GoalState.diag (goalState: GoalState) (parent?: Option GoalState :
         then instantiateAll decl.type
         else pure $ decl.type
       let type_sexp ← if options.printSexp then
-          let sexp ← serializeExpressionSexp type (sanitize := false)
+          let sexp ← serializeExpressionSexp type
           pure <| " " ++ sexp
         else
           pure ""
diff --git a/Test/Delate.lean b/Test/Delate.lean
index d918dc8..013be73 100644
--- a/Test/Delate.lean
+++ b/Test/Delate.lean
@@ -35,7 +35,7 @@ def test_sexp_of_symbol (env: Environment): IO LSpec.TestSeq := do
     ("Nat.add", "(:forall a (:c Nat) (:forall a (:c Nat) (:c Nat)))"),
     -- These ones are normal and easy
     ("Nat.add_one", "(: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)))"),
-    ("Nat.le_of_succ_le", "(:forall n (:c Nat) (:forall m (:c Nat) (:forall h ((:c LE.le) (:c Nat) (:c instLENat) ((:c Nat.succ) 1) 0) ((:c LE.le) (:c Nat) (:c instLENat) 2 1)) :implicit) :implicit)"),
+    ("Nat.le_of_succ_le", "(:forall n (:c Nat) (:forall m (:c Nat) (:forall h ((:c LE.le) (:c Nat) (:c instLENat) ((:c Nat.succ) 1) 0) ((:c LE.le) (:c Nat) (:c instLENat) 2 1)) :i) :i)"),
     -- Handling of higher order types
     ("Or", "(:forall a (:sort 0) (:forall b (:sort 0) (:sort 0)))"),
     ("List", "(:forall α (:sort (+ u 1)) (:sort (+ u 1)))")
@@ -50,8 +50,8 @@ def test_sexp_of_elab (env: Environment): IO LSpec.TestSeq := do
   let entries: List (String × (List Name) × String) := [
     ("λ x: Nat × Bool => x.1", [], "(:lambda x ((:c Prod) (:c Nat) (:c Bool)) ((:c Prod.fst) (:c Nat) (:c Bool) 0))"),
     ("λ x: Array Nat => x.data", [], "(:lambda x ((:c Array) (:c Nat)) ((:c Array.data) (:c Nat) 0))"),
-    ("λ {α: Sort (u + 1)} => List α", [`u], "(:lambda α (:sort (+ u 1)) ((:c List) 0) :implicit)"),
-    ("λ {α} => List α", [], "(:lambda α (:sort (+ (:mv _uniq.4) 1)) ((:c List) 0) :implicit)"),
+    ("λ {α: Sort (u + 1)} => List α", [`u], "(:lambda α (:sort (+ u 1)) ((:c List) 0) :i)"),
+    ("λ {α} => List α", [], "(:lambda α (:sort (+ (:mv _uniq.4) 1)) ((:c List) 0) :i)"),
     ("(2: Nat) <= (5: Nat)", [], "((:c LE.le) (:mv _uniq.18) (:mv _uniq.19) ((:c OfNat.ofNat) (:mv _uniq.4) (:lit 2) (:mv _uniq.5)) ((:c OfNat.ofNat) (:mv _uniq.14) (:lit 5) (:mv _uniq.15)))"),
   ]
   entries.foldlM (λ suites (source, levels, target) =>
@@ -77,7 +77,7 @@ def test_sexp_of_expr (env: Environment): IO LSpec.TestSeq := do
             .default)
         .implicit)
       .implicit,
-      "(:lambda p (:sort 0) (:lambda q (:sort 0) (:lambda k ((:c And) 1 0) ((:c And.right) _ _ 0)) :implicit) :implicit)"
+      "(:lambda p (:sort 0) (:lambda q (:sort 0) (:lambda k ((:c And) 1 0) ((:c And.right) _ _ 0)) :i) :i)"
     ),
   ]
   let termElabM: Elab.TermElabM LSpec.TestSeq := entries.foldlM (λ suites (expr, target) => do
diff --git a/Test/Proofs.lean b/Test/Proofs.lean
index a6b5487..104a849 100644
--- a/Test/Proofs.lean
+++ b/Test/Proofs.lean
@@ -97,7 +97,7 @@ def test_identity: TestM Unit := do
   addTest $ LSpec.check tactic ((← state1.serializeGoals (options := ← read)).map (·.name) =
     #[inner])
   let state1parent ← state1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!) (sanitize := false)
+    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!)
   addTest $ LSpec.test "(1 parent)" (state1parent == s!"(:lambda p (:sort 0) (:lambda h 0 (:subst (:mv {inner}) 1 0)))")
 
 -- Individual test cases
@@ -259,7 +259,7 @@ def test_or_comm: TestM Unit := do
   addTest $ LSpec.check "(1 root)" state1.rootExpr?.isNone
 
   let state1parent ← state1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!) (sanitize := false)
+    serializeExpressionSexp (← instantiateAll state1.parentExpr?.get!)
   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.tacticOn (goalId := 0) (tactic := tactic) with
@@ -276,7 +276,7 @@ def test_or_comm: TestM Unit := do
   addTest $ LSpec.check "(2 root)" state2.rootExpr?.isNone
 
   let state2parent ← state2.withParentContext do
-    serializeExpressionSexp (← instantiateAll state2.parentExpr?.get!) (sanitize := false)
+    serializeExpressionSexp (← instantiateAll state2.parentExpr?.get!)
   let orPQ := s!"((:c Or) (:fv {fvP}) (:fv {fvQ}))"
   let orQP := s!"((:c Or) (:fv {fvQ}) (:fv {fvP}))"
   let motive := s!"(:lambda t {orPQ} (:forall h ((:c Eq) ((:c Or) (:fv {fvP}) (:fv {fvQ})) (:fv {fvH}) 0) {orQP}))"
@@ -292,7 +292,7 @@ def test_or_comm: TestM Unit := do
       addTest $ assertUnreachable $ other.toString
       return ()
   let state3_1parent ← state3_1.withParentContext do
-    serializeExpressionSexp (← instantiateAll state3_1.parentExpr?.get!) (sanitize := false)
+    serializeExpressionSexp (← instantiateAll state3_1.parentExpr?.get!)
   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.tacticOn (goalId := 0) (tactic := "assumption") with