diff --git a/examples/prompt.js b/examples/prompt.js
index 740fd44..c17e27d 100644
--- a/examples/prompt.js
+++ b/examples/prompt.js
@@ -2,12 +2,13 @@ import { select, number, input } from '@inquirer/prompts';
 import { ModulePoint } from "../lib/point.js";
 import { DefaultMap } from "../util/defaultmap.js";
 import { pretty } from '../util/pretty.js';
-import { isFunction, prettyT } from '../structures/types.js';
+import { isFunction } from '../structures/types.js';
 import { ModuleStd } from '../stdlib.js';
 import { Double, GenericType, Int, SymbolT, Type } from "../primitives/types.js";
 import { eqType } from '../primitives/type.js';
 import { Any } from "../primitives/types.js";
 import { assignFn, makeGeneric, onlyOccurring } from '../generics/generics.js';
+import { prettyT } from '../util/pretty.js';
 
 
 // import {emitKeypressEvents} from 'node:readline';
diff --git a/generics/generics.js b/generics/generics.js
index 93c0371..5a987dc 100644
--- a/generics/generics.js
+++ b/generics/generics.js
@@ -1,7 +1,7 @@
 import { eqType } from "../primitives/type.js";
 import { zip } from "../util/util.js";
 import { pretty } from '../util/pretty.js';
-import { prettyT } from "../structures/types.js";
+import { prettyT } from "../util/pretty.js";
 
 // constructor for generic types
 //   for instance, the type:
diff --git a/structures/types.js b/structures/types.js
index 12bc350..7526a33 100644
--- a/structures/types.js
+++ b/structures/types.js
@@ -52,36 +52,3 @@ export const lsType = makeTypeConstructor(symbolList)(1);
 
 export const symbolSet = Symbol('Set');
 export const setType = makeTypeConstructor(symbolSet)(1);
-
-
-// Pretty print type
-export function prettyT(type) {
-  // console.log("pretty:", type);
-  if (typeof type === "symbol") {
-    return type.description;
-  }
-  if (type.typeVars) {
-    if (type.typeVars.size > 0) {
-      return `∀${[...type.typeVars].map(prettyT).sort((a,b)=>a.localeCompare(b)).join(",")}: ${prettyT(type.type)}`;
-    }
-    else {
-      return prettyT(type.type);
-    }
-  }
-  if (type.symbol === symbolFunction) {
-    return `(${prettyT(type.params[0])} -> ${prettyT(type.params[1])})`;
-  }
-  if (type.symbol === symbolList) {
-    return `[${prettyT(type.params[0])}]`;
-  }
-  if (type.symbol === symbolProduct) {
-    return `(${prettyT(type.params[0])} × ${prettyT(type.params[1])})`;
-  }
-  if (type.symbol === symbolSum) {
-    return `(${prettyT(type.params[0])} | ${prettyT(type.params[1])})`;
-  }
-  if (type.params.length === 0) {
-    return type.symbol.description;
-  }
-  return `${type.symbol.description}(${type.params.map(prettyT).join(", ")})`;
-}
diff --git a/util/pretty.js b/util/pretty.js
index 9b0681b..fbf0c93 100644
--- a/util/pretty.js
+++ b/util/pretty.js
@@ -1,5 +1,38 @@
 import { inspect } from 'node:util';
+import { symbolFunction, symbolList, symbolProduct, symbolSum } from '../structures/types.js';
 
 export function pretty(obj) {
   return inspect(obj, { colors: true, depth: null, breakLength: 120 });
 }
+
+// Pretty print type
+export function prettyT(type) {
+  // console.log("pretty:", type);
+  if (typeof type === "symbol") {
+    return type.description;
+  }
+  if (type.typeVars) {
+    if (type.typeVars.size > 0) {
+      return `∀${[...type.typeVars].map(prettyT).sort((a, b) => a.localeCompare(b)).join(",")}: ${prettyT(type.type)}`;
+    }
+    else {
+      return prettyT(type.type);
+    }
+  }
+  if (type.symbol === symbolFunction) {
+    return `(${prettyT(type.params[0])} -> ${prettyT(type.params[1])})`;
+  }
+  if (type.symbol === symbolList) {
+    return `[${prettyT(type.params[0])}]`;
+  }
+  if (type.symbol === symbolProduct) {
+    return `(${prettyT(type.params[0])} × ${prettyT(type.params[1])})`;
+  }
+  if (type.symbol === symbolSum) {
+    return `(${prettyT(type.params[0])} | ${prettyT(type.params[1])})`;
+  }
+  if (type.params.length === 0) {
+    return type.symbol.description;
+  }
+  return `${type.symbol.description}(${type.params.map(prettyT).join(", ")})`;
+}
diff --git a/versioning/types.js b/versioning/types.js
index 8068653..ac55fb0 100644
--- a/versioning/types.js
+++ b/versioning/types.js
@@ -3,7 +3,8 @@ import { Int } from "../primitives/types.js";
 import { enumType } from "../structures/enum.js";
 import { newProduct } from "../structures/product.js";
 import { structType } from "../structures/struct.js";
-import { prettyT, prodType } from "../structures/types.js";
+import { prodType } from "../structures/types.js";
+import { prettyT } from "../util/pretty.js";
 
 const Slot = structType([
   newProduct("value")(() => Value),