diff --git a/lib/stdlib.js b/lib/stdlib.js
index c1e7469..b03fb0f 100644
--- a/lib/stdlib.js
+++ b/lib/stdlib.js
@@ -17,6 +17,7 @@ import { ModuleCompareTypes } from "./compare/type.types.js";
 import { ModuleComparePrimitives } from "./compare/primitives.types.js";
 import { ModuleCompareStructures } from "./compare/structures.types.js";
 import { ModuleCompareDynamic } from "./compare/dynamic.types.js";
+import { ModuleVersioning } from "./versioning/types.js";
 
 export const ModuleStd = [
   // Symbols (for nominal types)
@@ -47,4 +48,7 @@ export const ModuleStd = [
   ...ModuleComparePrimitives,
   ...ModuleCompareStructures,
   ...ModuleCompareDynamic,
+
+  // Versioning
+  ...ModuleVersioning,
 ];
diff --git a/lib/versioning/types.js b/lib/versioning/types.js
index a4b0284..f37f06a 100644
--- a/lib/versioning/types.js
+++ b/lib/versioning/types.js
@@ -1,47 +1,94 @@
-import { makeGeneric } from "../generics/generics.js";
 import { makeTypeConstructor } from "../meta/type_constructor.js";
-import { Int, UUID } from "../primitives/primitive_types.js";
-import { enumType, makeModuleEnum } from "../structures/enum.types.js";
-import { newProduct } from "../structures/product.js";
-import { structType } from "../structures/struct.types.js";
-import { prettyT } from "../util/pretty.js";
+import { getDefaultTypeParser, makeTypeParser } from "../parser/type_parser.js";
+import { Dynamic, Int, UUID } from "../primitives/primitive_types.js";
+import { makeModuleEnum } from "../structures/enum.types.js";
+import { makeModuleStruct } from "../structures/struct.types.js";
 
-const Slot = makeTypeConstructor("Slot__318d1c1a9336c141336c461c6a3207b0")(1);
-const Value = makeTypeConstructor("Value__23fc00a2db1374bd3dc1a0ad2d8517ab")(1);
-
-makeModuleEnum(Value)([
+export const Slot = makeTypeConstructor("Slot__318d1c1a9336c141336c461c6a3207b0")(0);
+export const Value = makeTypeConstructor("Value__23fc00a2db1374bd3dc1a0ad2d8517ab")(0);
+export const Transformation = makeTypeConstructor("Transformation__9eac70d7020c7c45d5a16f3f14b13083")(0);
+export const Write = makeTypeConstructor("Write__abaef8ddb5c167b5d2cedac111fcefd3")(0);
 
+// Enum: Value
+const [
+  // constructors
+  [, {i: newValueLiteral}],
+  [, {i: newValueRead}],
+  [, {i: newValueTransform}],
+  // match function
+  [, {i: matchValue}],
+] = makeModuleEnum(Value)([
+  {l: "literal"  , r: Dynamic},
+  {l: "read"     , r: Slot},
+  {l: "transform", r: Transformation},
 ]);
 
-const _slotType = a => Value => structType([
-  newProduct("value")(_ => Value || _valueType(a)(Slot)),
-  newProduct("rest" )(_ => enumType([
-    newProduct("new")(Slot => structType([
-      newProduct("uuid" )(_ => UUID),
-      newProduct("value")(_ => Value || _valueType(a)(Slot)),
-    ])),
-    newProduct("overwrites")(Slot => structType([
-      newProduct("slot" )(_ => Slot),
-      newProduct("value")(_ => Value || _valueType(a)(Slot)),
-      newProduct("depth")(_ => Int),
-    ])),
-  ])),
+// Enum: Slot
+const [
+  // constructors
+  [, {i: newSlotNew}],
+  [, {i: newSlotWrite}],
+  // match function
+  [, {i: matchSlot}],
+] = makeModuleEnum(Slot)([
+  {l: "new"  , r: UUID},
+  {l: "write", r: Write},
 ]);
 
-const _valueType = a => Slot => enumType([
-  newProduct("literal"  )(_ => a),
-  newProduct("read"     )(Value => Slot || _slotType(a)(Value)),
-  newProduct("transform")(Value => structType([
-    newProduct("in" )(_ => Value),
-    newProduct("fn" )(_ => Value),
-    newProduct("out")(_ => a),
-  ])),
+// Struct: Transformation
+const [
+  // constructor
+  [, {i: newTransformation}],
+  // getters
+  // [, {i: getInput}],
+  // [, {i: getFn}],
+  // [, {i: getOutput}],
+] = makeModuleStruct(Transformation)([
+  {l: "input" , r: Value},
+  {l: "fn"    , r: Value},
+  {l: "output", r: Value},
 ]);
 
-const slotType = makeGeneric(a => _slotType(a)(null));
-const valueType = makeGeneric(a => _valueType(a)(null));
+// Struct: Write
+const [
+  // constructor
+  [, {i: newWrite}],
+  // getters
+  // [, {i: getSlot}],
+  // [, {i: getValue}],
+  // [, {i: getDepth}],
+] = makeModuleStruct(Write)([
+  {l: "slot", r: Slot},
+  {l: "value", r: Value},
+  {l: "depth", r: Int},
+]);
 
-console.log("slotType:", prettyT(slotType));
-console.log("valueType:", prettyT(valueType));
+// shorthands
+export const getDepth = slot =>
+  matchSlot(slot)
+    (_slotNew  => 0)
+    (slotWrite => slotWrite.depth);
+export const overwrite = slot => value =>
+  newSlotWrite(
+    newWrite(slot)(value)(getDepth(slot)+1)
+  );
+export const read = newValueRead;
+export const transform = inValue => fnValue => newValueTransform(newTransformation(inValue)(fnValue));
+export const newSlot = newSlotNew;
+export const newLiteral = newValueLiteral;
 
-// const valueType = makeGeneric(a => _valueType(a)(_slotType));
\ No newline at end of file
+const mkType = makeTypeParser({
+  extraPrimitives: [
+    ["Value", Value],
+    ["Slot", Slot],
+  ]
+});
+
+export const ModuleVersioning = [
+  ["getDepth", {i: getDepth, t: mkType("Slot -> Int")}],
+  ["overwrite", {i: overwrite, t: mkType("Slot -> Value -> Slot")}],
+  ["read", {i: read, t: mkType("Slot -> Value")}],
+  ["transform", {i: transform, t: mkType("Value -> Value -> Value")}],
+  ["newSlot", {i: newSlot, t: mkType("UUID -> Slot")}],
+  ["newLiteral", {i: newLiteral, t: mkType("Dynamic -> Value")}],
+];