diff --git a/packages/squiggle-lang/src/rescript/interpreter/AST.res b/packages/squiggle-lang/src/rescript/interpreter/AST.res
index 6680db90..2bc93459 100644
--- a/packages/squiggle-lang/src/rescript/interpreter/AST.res
+++ b/packages/squiggle-lang/src/rescript/interpreter/AST.res
@@ -1,6 +1,6 @@
 open ASTTypes.AST
 
-let toString = ASTBasic.toString
+let toString = ASTTypes.Node.toString
 
 let envs = (samplingInputs, environment) => {
   samplingInputs: samplingInputs,
diff --git a/packages/squiggle-lang/src/rescript/interpreter/ASTBasic.res b/packages/squiggle-lang/src/rescript/interpreter/ASTBasic.res
deleted file mode 100644
index b0806c82..00000000
--- a/packages/squiggle-lang/src/rescript/interpreter/ASTBasic.res
+++ /dev/null
@@ -1,27 +0,0 @@
-open ASTTypes.AST
-// This file exists to manage a dependency cycle. It would be good to refactor later.
-
-let rec toString: node => string = x =>
-  switch x {
-  | #SymbolicDist(d) => SymbolicDist.T.toString(d)
-  | #RenderedDist(_) => "[renderedShape]"
-  | #AlgebraicCombination(op, t1, t2) => Operation.Algebraic.format(op, toString(t1), toString(t2))
-  | #PointwiseCombination(op, t1, t2) => Operation.Pointwise.format(op, toString(t1), toString(t2))
-  | #Normalize(t) => "normalize(k" ++ (toString(t) ++ ")")
-  | #Truncate(lc, rc, t) => Operation.T.truncateToString(lc, rc, toString(t))
-  | #Render(t) => toString(t)
-  | #Symbol(t) => "Symbol: " ++ t
-  | #FunctionCall(name, args) =>
-    "[Function call: (" ++
-    (name ++
-    ((args |> E.A.fmap(toString) |> Js.String.concatMany(_, ",")) ++ ")]"))
-  | #Function(args, internal) =>
-    "[Function: (" ++ ((args |> Js.String.concatMany(_, ",")) ++ (toString(internal) ++ ")]"))
-  | #Array(a) => "[" ++ ((a |> E.A.fmap(toString) |> Js.String.concatMany(_, ",")) ++ "]")
-  | #Hash(h) =>
-    "{" ++
-    ((h
-    |> E.A.fmap(((name, value)) => name ++ (":" ++ toString(value)))
-    |> Js.String.concatMany(_, ",")) ++
-    "}")
-  }
\ No newline at end of file
diff --git a/packages/squiggle-lang/src/rescript/interpreter/ASTEvaluator.res b/packages/squiggle-lang/src/rescript/interpreter/ASTEvaluator.res
index ba2929f0..53123ee5 100644
--- a/packages/squiggle-lang/src/rescript/interpreter/ASTEvaluator.res
+++ b/packages/squiggle-lang/src/rescript/interpreter/ASTEvaluator.res
@@ -56,7 +56,7 @@ module AlgebraicCombination = {
 
   let operationToLeaf = (
     evaluationParams: evaluationParams,
-    algebraicOp: ASTTypes.algebraicOperation,
+    algebraicOp: Operation.algebraicOperation,
     t1: t,
     t2: t,
   ): result<node, string> =>
@@ -106,7 +106,7 @@ module PointwiseCombination = {
 
   let operationToLeaf = (
     evaluationParams: evaluationParams,
-    pointwiseOp: pointwiseOperation,
+    pointwiseOp: Operation.pointwiseOperation,
     t1: t,
     t2: t,
   ) =>
diff --git a/packages/squiggle-lang/src/rescript/interpreter/ASTTypes.res b/packages/squiggle-lang/src/rescript/interpreter/ASTTypes.res
index 5c76df13..b9a1049d 100644
--- a/packages/squiggle-lang/src/rescript/interpreter/ASTTypes.res
+++ b/packages/squiggle-lang/src/rescript/interpreter/ASTTypes.res
@@ -1,20 +1,3 @@
-type algebraicOperation = [
-  | #Add
-  | #Multiply
-  | #Subtract
-  | #Divide
-  | #Exponentiate
-]
-type pointwiseOperation = [#Add | #Multiply | #Exponentiate]
-type scaleOperation = [#Multiply | #Exponentiate | #Log]
-type distToFloatOperation = [
-  | #Pdf(float)
-  | #Cdf(float)
-  | #Inv(float)
-  | #Mean
-  | #Sample
-]
-
 module AST = {
   type rec hash = array<(string, node)>
   and node = [
@@ -24,8 +7,8 @@ module AST = {
     | #Hash(hash)
     | #Array(array<node>)
     | #Function(array<string>, node)
-    | #AlgebraicCombination(algebraicOperation, node, node)
-    | #PointwiseCombination(pointwiseOperation, node, node)
+    | #AlgebraicCombination(Operation.algebraicOperation, node, node)
+    | #PointwiseCombination(Operation.pointwiseOperation, node, node)
     | #Normalize(node)
     | #Render(node)
     | #Truncate(option<float>, option<float>, node)
@@ -172,3 +155,32 @@ module Program = {
   ]
   type program = array<statement>
 }
+
+module Node = {
+  let rec toString: AST.node => string = x =>
+    switch x {
+    | #SymbolicDist(d) => SymbolicDist.T.toString(d)
+    | #RenderedDist(_) => "[renderedShape]"
+    | #AlgebraicCombination(op, t1, t2) =>
+      Operation.Algebraic.format(op, toString(t1), toString(t2))
+    | #PointwiseCombination(op, t1, t2) =>
+      Operation.Pointwise.format(op, toString(t1), toString(t2))
+    | #Normalize(t) => "normalize(k" ++ (toString(t) ++ ")")
+    | #Truncate(lc, rc, t) => Operation.Truncate.toString(lc, rc, toString(t))
+    | #Render(t) => toString(t)
+    | #Symbol(t) => "Symbol: " ++ t
+    | #FunctionCall(name, args) =>
+      "[Function call: (" ++
+      (name ++
+      ((args |> E.A.fmap(toString) |> Js.String.concatMany(_, ",")) ++ ")]"))
+    | #Function(args, internal) =>
+      "[Function: (" ++ ((args |> Js.String.concatMany(_, ",")) ++ (toString(internal) ++ ")]"))
+    | #Array(a) => "[" ++ ((a |> E.A.fmap(toString) |> Js.String.concatMany(_, ",")) ++ "]")
+    | #Hash(h) =>
+      "{" ++
+      ((h
+      |> E.A.fmap(((name, value)) => name ++ (":" ++ toString(value)))
+      |> Js.String.concatMany(_, ",")) ++
+      "}")
+    }
+}
diff --git a/packages/squiggle-lang/src/rescript/interpreter/typeSystem/HardcodedFunctions.res b/packages/squiggle-lang/src/rescript/interpreter/typeSystem/HardcodedFunctions.res
index 3e06ae71..5bf93c4d 100644
--- a/packages/squiggle-lang/src/rescript/interpreter/typeSystem/HardcodedFunctions.res
+++ b/packages/squiggle-lang/src/rescript/interpreter/typeSystem/HardcodedFunctions.res
@@ -84,7 +84,7 @@ let makeDist = (name, fn) =>
   )
 
 let floatFromDist = (
-  distToFloatOp: ASTTypes.distToFloatOperation,
+  distToFloatOp: Operation.distToFloatOperation,
   t: TypeSystem.samplingDist,
 ): result<node, string> =>
   switch t {
diff --git a/packages/squiggle-lang/src/rescript/interpreter/typeSystem/TypeSystem.res b/packages/squiggle-lang/src/rescript/interpreter/typeSystem/TypeSystem.res
index 2989f1c0..9535e40e 100644
--- a/packages/squiggle-lang/src/rescript/interpreter/typeSystem/TypeSystem.res
+++ b/packages/squiggle-lang/src/rescript/interpreter/typeSystem/TypeSystem.res
@@ -61,7 +61,7 @@ module TypedValue = {
       |> E.A.fmap(((name, t)) => fromNode(t) |> E.R.fmap(r => (name, r)))
       |> E.A.R.firstErrorOrOpen
       |> E.R.fmap(r => #Hash(r))
-    | e => Error("Wrong type: " ++ ASTBasic.toString(e))
+    | e => Error("Wrong type: " ++ ASTTypes.Node.toString(e))
     }
 
   // todo: Arrays and hashes
diff --git a/packages/squiggle-lang/src/rescript/pointSetDist/AlgebraicShapeCombination.res b/packages/squiggle-lang/src/rescript/pointSetDist/AlgebraicShapeCombination.res
index 44ab740f..6e22c349 100644
--- a/packages/squiggle-lang/src/rescript/pointSetDist/AlgebraicShapeCombination.res
+++ b/packages/squiggle-lang/src/rescript/pointSetDist/AlgebraicShapeCombination.res
@@ -96,7 +96,7 @@ let toDiscretePointMassesFromTriangulars = (
 }
 
 let combineShapesContinuousContinuous = (
-  op: ASTTypes.algebraicOperation,
+  op: Operation.algebraicOperation,
   s1: PointSetTypes.xyShape,
   s2: PointSetTypes.xyShape,
 ): PointSetTypes.xyShape => {
@@ -200,7 +200,7 @@ let toDiscretePointMassesFromDiscrete = (s: PointSetTypes.xyShape): pointMassesW
 }
 
 let combineShapesContinuousDiscrete = (
-  op: ASTTypes.algebraicOperation,
+  op: Operation.algebraicOperation,
   continuousShape: PointSetTypes.xyShape,
   discreteShape: PointSetTypes.xyShape,
 ): PointSetTypes.xyShape => {
diff --git a/packages/squiggle-lang/src/rescript/pointSetDist/Continuous.res b/packages/squiggle-lang/src/rescript/pointSetDist/Continuous.res
index 0dd0924d..92654b35 100644
--- a/packages/squiggle-lang/src/rescript/pointSetDist/Continuous.res
+++ b/packages/squiggle-lang/src/rescript/pointSetDist/Continuous.res
@@ -211,7 +211,7 @@ module T = Dist({
 /* This simply creates multiple copies of the continuous distribution, scaled and shifted according to
  each discrete data point, and then adds them all together. */
 let combineAlgebraicallyWithDiscrete = (
-  op: ASTTypes.algebraicOperation,
+  op: Operation.algebraicOperation,
   t1: t,
   t2: PointSetTypes.discreteShape,
 ) => {
@@ -244,7 +244,7 @@ let combineAlgebraicallyWithDiscrete = (
   }
 }
 
-let combineAlgebraically = (op: ASTTypes.algebraicOperation, t1: t, t2: t) => {
+let combineAlgebraically = (op: Operation.algebraicOperation, t1: t, t2: t) => {
   let s1 = t1 |> getShape
   let s2 = t2 |> getShape
   let t1n = s1 |> XYShape.T.length
diff --git a/packages/squiggle-lang/src/rescript/pointSetDist/Discrete.res b/packages/squiggle-lang/src/rescript/pointSetDist/Discrete.res
index 65828461..fd1cedd6 100644
--- a/packages/squiggle-lang/src/rescript/pointSetDist/Discrete.res
+++ b/packages/squiggle-lang/src/rescript/pointSetDist/Discrete.res
@@ -85,7 +85,7 @@ let updateIntegralCache = (integralCache, t: t): t => {
 
 /* This multiples all of the data points together and creates a new discrete distribution from the results.
  Data points at the same xs get added together. It may be a good idea to downsample t1 and t2 before and/or the result after. */
-let combineAlgebraically = (op: ASTTypes.algebraicOperation, t1: t, t2: t): t => {
+let combineAlgebraically = (op: Operation.algebraicOperation, t1: t, t2: t): t => {
   let t1s = t1 |> getShape
   let t2s = t2 |> getShape
   let t1n = t1s |> XYShape.T.length
diff --git a/packages/squiggle-lang/src/rescript/pointSetDist/Mixed.res b/packages/squiggle-lang/src/rescript/pointSetDist/Mixed.res
index dcdb2c2f..8c7b99ed 100644
--- a/packages/squiggle-lang/src/rescript/pointSetDist/Mixed.res
+++ b/packages/squiggle-lang/src/rescript/pointSetDist/Mixed.res
@@ -227,7 +227,7 @@ module T = Dist({
   }
 })
 
-let combineAlgebraically = (op: ASTTypes.algebraicOperation, t1: t, t2: t): t => {
+let combineAlgebraically = (op: Operation.algebraicOperation, t1: t, t2: t): t => {
   // Discrete convolution can cause a huge increase in the number of samples,
   // so we'll first downsample.
 
diff --git a/packages/squiggle-lang/src/rescript/pointSetDist/PointSetDist.res b/packages/squiggle-lang/src/rescript/pointSetDist/PointSetDist.res
index caf0fa1f..41e84fee 100644
--- a/packages/squiggle-lang/src/rescript/pointSetDist/PointSetDist.res
+++ b/packages/squiggle-lang/src/rescript/pointSetDist/PointSetDist.res
@@ -33,7 +33,7 @@ let toMixed = mapToAll((
     ),
 ))
 
-let combineAlgebraically = (op: ASTTypes.algebraicOperation, t1: t, t2: t): t =>
+let combineAlgebraically = (op: Operation.algebraicOperation, t1: t, t2: t): t =>
   switch (t1, t2) {
   | (Continuous(m1), Continuous(m2)) =>
     Continuous.combineAlgebraically(op, m1, m2) |> Continuous.T.toPointSetDist
@@ -197,7 +197,7 @@ let sampleNRendered = (n, dist) => {
   doN(n, () => sample(distWithUpdatedIntegralCache))
 }
 
-let operate = (distToFloatOp: ASTTypes.distToFloatOperation, s): float =>
+let operate = (distToFloatOp: Operation.distToFloatOperation, s): float =>
   switch distToFloatOp {
   | #Pdf(f) => pdf(f, s)
   | #Cdf(f) => pdf(f, s)
diff --git a/packages/squiggle-lang/src/rescript/symbolicDist/SymbolicDist.res b/packages/squiggle-lang/src/rescript/symbolicDist/SymbolicDist.res
index aa02f32a..3da6bd02 100644
--- a/packages/squiggle-lang/src/rescript/symbolicDist/SymbolicDist.res
+++ b/packages/squiggle-lang/src/rescript/symbolicDist/SymbolicDist.res
@@ -272,7 +272,7 @@ module T = {
     | #Float(n) => Float.mean(n)
     }
 
-  let operate = (distToFloatOp: ASTTypes.distToFloatOperation, s) =>
+  let operate = (distToFloatOp: Operation.distToFloatOperation, s) =>
     switch distToFloatOp {
     | #Cdf(f) => Ok(cdf(f, s))
     | #Pdf(f) => Ok(pdf(f, s))
@@ -302,7 +302,7 @@ module T = {
   let tryAnalyticalSimplification = (
     d1: symbolicDist,
     d2: symbolicDist,
-    op: ASTTypes.algebraicOperation,
+    op: Operation.algebraicOperation,
   ): analyticalSimplificationResult =>
     switch (d1, d2) {
     | (#Float(v1), #Float(v2)) =>
diff --git a/packages/squiggle-lang/src/rescript/interpreter/Operation.res b/packages/squiggle-lang/src/rescript/utility/Operation.res
similarity index 72%
rename from packages/squiggle-lang/src/rescript/interpreter/Operation.res
rename to packages/squiggle-lang/src/rescript/utility/Operation.res
index f5a120a8..dc29bc71 100644
--- a/packages/squiggle-lang/src/rescript/interpreter/Operation.res
+++ b/packages/squiggle-lang/src/rescript/utility/Operation.res
@@ -1,4 +1,21 @@
-open ASTTypes
+// This file has no dependencies. It's used outside of the interpreter, but the interpreter depends on it.
+
+type algebraicOperation = [
+  | #Add
+  | #Multiply
+  | #Subtract
+  | #Divide
+  | #Exponentiate
+]
+type pointwiseOperation = [#Add | #Multiply | #Exponentiate]
+type scaleOperation = [#Multiply | #Exponentiate | #Log]
+type distToFloatOperation = [
+  | #Pdf(float)
+  | #Cdf(float)
+  | #Inv(float)
+  | #Mean
+  | #Sample
+]
 
 module Algebraic = {
   type t = algebraicOperation
@@ -86,22 +103,10 @@ module Scale = {
     }
 }
 
-module T = {
-  let truncateToString = (left: option<float>, right: option<float>, nodeToString) => {
+module Truncate = {
+  let toString = (left: option<float>, right: option<float>, nodeToString) => {
     let left = left |> E.O.dimap(Js.Float.toString, () => "-inf")
     let right = right |> E.O.dimap(Js.Float.toString, () => "inf")
     j`truncate($nodeToString, $left, $right)`
   }
-  let toString = (nodeToString, x) =>
-    switch x {
-    | #AlgebraicCombination(op, t1, t2) => Algebraic.format(op, nodeToString(t1), nodeToString(t2))
-    | #PointwiseCombination(op, t1, t2) => Pointwise.format(op, nodeToString(t1), nodeToString(t2))
-    | #VerticalScaling(scaleOp, t, scaleBy) =>
-      Scale.format(scaleOp, nodeToString(t), nodeToString(scaleBy))
-    | #Normalize(t) => "normalize(k" ++ (nodeToString(t) ++ ")")
-    | #FloatFromDist(floatFromDistOp, t) => DistToFloat.format(floatFromDistOp, nodeToString(t))
-    | #Truncate(lc, rc, t) => truncateToString(lc, rc, nodeToString(t))
-    | #Render(t) => nodeToString(t)
-    | _ => ""
-    } // SymbolicDist and RenderedDist are handled in AST.toString.
-}
+}
\ No newline at end of file