diff --git a/lib/versioning/merge.js b/lib/versioning/merge.js
index ae80a03..7ef70ba 100644
--- a/lib/versioning/merge.js
+++ b/lib/versioning/merge.js
@@ -1,5 +1,5 @@
-import { emptySet, add, length, forEach, has, remove } from "../structures/set.js";
-import { getDepth, Slot } from "./value_slot.js";
+import { emptySet, add, length, forEach, union, has } from "../structures/set.js";
+import { getDepth, Slot, Value, Write } from "./value_slot.js";
 import { compareSlot } from "./compare.js";
 import { makeTypeParser } from "../parser/type_parser.js";
 import { newDynamic } from "../primitives/dynamic.js";
@@ -20,10 +20,6 @@ export const findLCA = slotA => slotB => {
   }
 };
 
-// returns
-//  {slotA} if slotA is younger
-//  {slotB} if slotB is younger
-//  {slotA, slotB} if they are concurrent (conflicting)
 export const merge = slotA => slotB => {
   const lca = findLCA(slotA)(slotB);
   if (compareSlot(lca)(slotA) === 0) {
@@ -38,7 +34,7 @@ export const merge = slotA => slotB => {
 };
 
 export const mergeN = slots => {
-  let result = slots;
+  let toDelete = emptySetOfSlots;
   forEach(slots)(slotA => {
     forEach(slots)(slotB => {
       // compare all non-identical pairs
@@ -48,18 +44,26 @@ export const mergeN = slots => {
           // if in the pair, one is an ancestor of the other,
           // only keep the other
           if (has(m)(slotA)) {
-            result = remove(result)(slotB);
+            toDelete = add(toDelete)(slotB);
           }
         }
       }
     });
   });
+  let result = emptySetOfSlots;
+  forEach(slots)(slot => {
+    if (!has(toDelete)(slot)) {
+      result = add(result)(slot);
+    }
+  })
   return result;
 };
 
 const mkType = makeTypeParser({
   extraPrimitives: [
-    ["Slot" , Slot],
+    ["Value", Value],
+    ["Slot" , Slot ],
+    ["Write", Write],
   ],
 });
 
diff --git a/lib/versioning/static/compare.js b/lib/versioning/static/compare.js
deleted file mode 100644
index bfb8429..0000000
--- a/lib/versioning/static/compare.js
+++ /dev/null
@@ -1,55 +0,0 @@
-import { compareSymbols, compareInts } from "../../compare/primitives.js";
-import { compareFunctions } from "../../compare/structures.js";
-import { makeTypeParser } from "../../parser/type_parser.js";
-import { newDynamic } from "../../primitives/dynamic.js";
-import { makeEnumCompareFn } from "../../structures/enum.js";
-import { makeStructCompareFn } from "../../structures/struct.js";
-import { Slot, Transformation, Value, Write } from "./value_slot.js";
-
-
-// comparison functions are mutually recursive...
-
-export const compareSlot = compareElems => makeEnumCompareFn([
-  { l: "new", r: () => compareSymbols },
-  { l: "write", r: () => compareWrite(compareElems) },
-]);
-
-export const compareWrite = compareElems => makeStructCompareFn([
-  { l: "slot", r: () => compareSlot(compareElems) },
-  { l: "value", r: () => compareValue(compareElems) },
-  { l: "depth", r: () => compareInts },
-]);
-
-export const compareTransformation = compareInputs => compareOutputs => makeStructCompareFn([
-  { l: "input", r: () => compareValue(compareInputs) },
-  { l: "fn", r: () => compareValue(compareFunctions(compareInputs)(compareOutputs)) },
-  { l: "output", r: () => compareOutputs },
-]);
-
-export const compareValue = compareElems => makeEnumCompareFn([
-  { l: "literal", r: () => compareElems },
-  { l: "read", r: () => compareWrite(compareElems) },
-  { l: "transform", r: () =>
-    compareTransformation
-      (_a => _b => 0) // <- we cheat here, because we don't statically know the input type of the transformation.
-      (compareElems) },
-]);
-
-const mkType = makeTypeParser({
-  extraBracketOperators: [
-    [':=', ['=:', Slot]],
-    ['*=', ['=*', Value]],
-    ['*:=', ['=:*', Write]],
-  ],
-  extraInfixOperators: [
-    ['===>', Transformation],
-  ],
-});
-
-export const ModuleVersioningCompare = [
-  // comparison
-  ["compareSlot" , newDynamic(compareSlot )(mkType("(a -> a -> Ordering) ->  :=a=:  ->  :=a=:  -> Ordering"))],
-  ["compareValue", newDynamic(compareValue)(mkType("(a -> a -> Ordering) ->  *=a=*  ->  *=a=*  -> Ordering"))],
-  ["compareWrite", newDynamic(compareWrite)(mkType("(a -> a -> Ordering) -> *:=a=:* -> *:=a=:* -> Ordering"))],
-  ["compareTransformation", newDynamic(compareTransformation)(mkType("(a -> a -> Ordering) -> (b -> b -> Ordering) -> (a ===> b) -> (a ===> b) -> Ordering"))],
-];
diff --git a/lib/versioning/static/merge.js b/lib/versioning/static/merge.js
deleted file mode 100644
index 1243f7b..0000000
--- a/lib/versioning/static/merge.js
+++ /dev/null
@@ -1,69 +0,0 @@
-import { emptySet, add, length, forEach, has, remove } from "../../structures/set.js";
-import { getDepth, Slot } from "./value_slot.js";
-import { compareSlot } from "../compare.js";
-import { makeTypeParser } from "../../parser/type_parser.js";
-import { newDynamic } from "../../primitives/dynamic.js";
-
-const emptySetOfSlots = emptySet(compareSlot);
-
-export const findLCA = slotA => slotB => {
-  if (compareSlot(slotA)(slotB) === 0) {
-    return slotA;
-  }
-  if (getDepth(slotA) > getDepth(slotB)) {
-    // we can assume that slotA.variant === "write"
-    return findLCA(slotA.value.slot)(slotB);
-  }
-  else {
-    // we can assume that slotB.variant === "write"
-    return findLCA(slotA)(slotB.value.slot);
-  }
-};
-
-// returns
-//  {slotA} if slotA is younger
-//  {slotB} if slotB is younger
-//  {slotA, slotB} if they are concurrent (conflicting)
-export const merge = slotA => slotB => {
-  const lca = findLCA(slotA)(slotB);
-  if (compareSlot(lca)(slotA) === 0) {
-    return add(emptySetOfSlots)(slotB);
-  }
-  if (compareSlot(lca)(slotB) === 0) {
-    return add(emptySetOfSlots)(slotA);
-  }
-  const setWithA = add(emptySetOfSlots)(slotA);
-  const setWithAandB = add(setWithA)(slotB);
-  return setWithAandB;
-};
-
-export const mergeN = slots => {
-  let result = slots;
-  forEach(slots)(slotA => {
-    forEach(slots)(slotB => {
-      // compare all non-identical pairs
-      if (compareSlot(slotA)(slotB) !== 0) {
-        const m = merge(slotA)(slotB);
-        if (length(m) === 1) {
-          // if in the pair, one is an ancestor of the other,
-          // only keep the other
-          if (has(m)(slotA)) {
-            result = remove(result)(slotB);
-          }
-        }
-      }
-    });
-  });
-  return result;
-};
-
-const mkType = makeTypeParser({
-  extraBracketOperators: [
-    [':=', ['=:', Slot]],
-  ],
-});
-
-export const ModuleStaticMerge = [
-  ["merge" , newDynamic(merge)(mkType(":=a=: -> :=a=: -> {:=a=:}"))],
-  ["mergeN", newDynamic(merge)(mkType("{:=a=:} -> {:=a=:}"       ))],
-];
diff --git a/lib/versioning/static/value_slot.js b/lib/versioning/static/value_slot.js
deleted file mode 100644
index 7e680ab..0000000
--- a/lib/versioning/static/value_slot.js
+++ /dev/null
@@ -1,134 +0,0 @@
-import { makeGeneric } from "../../generics/generics.js";
-import { makeTypeConstructor } from "../../meta/type_constructor.js";
-import { makeTypeParser } from "../../parser/type_parser.js";
-import { apply, newDynamic } from "../../primitives/dynamic.js";
-import { Int, UUID } from "../../primitives/primitive_types.js";
-import { makeModuleEnum } from "../../structures/enum.types.js";
-import { makeModuleStruct } from "../../structures/struct.types.js";
-import { fnType } from "../../structures/type_constructors.types.js";
-
-// Value and Slot each take 1 type parameter
-export const Slot = makeTypeConstructor("Slot__318d1c1a9336c141336c461c6a3207b0")(1);
-export const Value = makeTypeConstructor("Value__23fc00a2db1374bd3dc1a0ad2d8517ab")(1);
-
-// Transformation takes 2 type parameters
-export const Transformation = makeTypeConstructor("Transformation__9eac70d7020c7c45d5a16f3f14b13083")(2);
-
-// A Write-operation writes a value to a slot. The inner type of the Value and Slot must match.
-export const Write = makeTypeConstructor("Write__abaef8ddb5c167b5d2cedac111fcefd3")(1);
-
-// Enum: Value
-const [
-  // constructors
-  [, {i: newValueLiteral}],
-  [, {i: newValueRead}],
-  [, {i: newValueTransform}],
-  // match function
-  [, {i: matchValue}],
-] = makeGeneric((innerType, a) => makeModuleEnum(Value(_=>innerType))([
-  {l: "literal"  , r: innerType},
-  {l: "read"     , r: Write(_=>innerType)}, // <- a 'read' reads the result of a Write (to a Slot)
-  {l: "transform", r: Transformation(_=>a)(_=>innerType)}, // <- result of a function call
-]));
-
-// Enum: Slot
-const [
-  // constructors
-  [, {i: newSlotNew}],
-  [, {i: newSlotWrite}],
-  // match function
-  [, {i: matchSlot}],
-] = makeGeneric(innerType => makeModuleEnum(Slot(_=>innerType))([
-  {l: "new"  , r: UUID },
-  {l: "write", r: Write},
-]));
-
-// Struct: Transformation (i.e., a function call)
-const [
-  // constructor
-  [, {i: newTransformation}],
-  // getters
-  // [, {i: getInput}],
-  // [, {i: getFn}],
-  // [, {i: getOutput}],
-] = makeGeneric((inType, outType) => makeModuleStruct(Transformation)([
-  {l: "input" , r: Value(_=>inType)  }, // <- the input is a value (e.g., could be the result of a Transformation itself)
-  {l: "fn"    , r: Value(_=>fnType(_=>inType)(_=>outType)) }, // <- the function is also a value (e.g., could also be result of a transformation, e.g., when currying)
-  {l: "output", r: outType}, // <- the result
-]));
-
-// Struct: Write
-const [
-  // constructor
-  [, {i: newWrite}],
-  // getters
-  // [, {i: getDepth}],
-  // [, {i: getSlot}],
-  // [, {i: getValue}],
-] = makeGeneric(innerType => makeModuleStruct(Write(_=>innerType))([
-  {l: "depth", r: Int  }, // <- depth increases merge performance, and also comes first in the struct (this way, it is the first value compared upon comparison)
-  {l: "slot" , r: Slot(_=>innerType) },
-  {l: "value", r: Value(_=>innerType) },
-]));
-
-// shorthands
-export const getDepth = slot =>
-  matchSlot(slot)
-    (_slotNew  => 0n)
-    (slotWrite => slotWrite.depth);
-
-// get the value from a Value
-export const getVal = value =>
-  matchValue(value)
-    (literal   => literal)
-    (read      => read.value.value)
-    (transform => transform.output)
-
-export const write = slot => value =>
-  newSlotWrite(
-    newWrite
-      (getDepth(slot)+1n)
-      (slot)
-      (value)
-  );
-
-export const transform = inValue => fnValue =>
-  newValueTransform
-    (newTransformation
-      (inValue)
-      (fnValue)
-      (apply(getVal(fnValue))(getVal(inValue))) // <- call function
-    );
-
-export const read = slot =>
-  matchSlot(slot)
-    (_slotNew => { throw new Error("cannot read empty slot"); })
-    (write => write.value);
-
-export const newSlot = newSlotNew;
-export const toSlot = newSlotWrite;
-export const newLiteral = newValueLiteral;
-
-const mkType = makeTypeParser({
-  extraBracketOperators: [
-    [':=', ['=:', Slot]],
-    ['*=', ['=*', Value]],
-  ],
-  extraInfixOperators: [
-    ['===>', Transformation],
-  ],
-});
-
-export const ModuleStaticVersioning = [
-  // slots
-  ["newSlot"   , newDynamic(newSlot   )(mkType("UUID -> :=a=:"          ))],
-  ["write"     , newDynamic(write     )(mkType(":=a=: -> *=a=* -> :=a=:"))],
-  ["getDepth"  , newDynamic(getDepth  )(mkType(":=a=: -> Int"           ))],
-
-  // values
-  ["newLiteral", newDynamic(newLiteral)(mkType("a -> *=a=*"                  ))],
-  ["read"      , newDynamic(read      )(mkType(":=a=: -> *=a=*"              ))],
-  ["transform" , newDynamic(transform )(mkType("*=a=* -> *=(a->b)=* -> *=b=*"))],
-];
-
-
diff --git a/lib/versioning/value_slot.js b/lib/versioning/value_slot.js
index dbbc64d..3784ae8 100644
--- a/lib/versioning/value_slot.js
+++ b/lib/versioning/value_slot.js
@@ -20,8 +20,8 @@ const [
   [, {i: matchValue}],
 ] = makeModuleEnum(Value)([
   {l: "literal"  , r: Dynamic},
-  {l: "read"     , r: Write}, // <- a 'read' reads the result of a Write (to a Slot)
-  {l: "transform", r: Transformation}, // <- result of a function call
+  {l: "read"     , r: Write}, // a 'read' reads the result of a Write
+  {l: "transform", r: Transformation},
 ]);
 
 // Enum: Slot
@@ -36,7 +36,7 @@ const [
   {l: "write", r: Write},
 ]);
 
-// Struct: Transformation (i.e., a function call)
+// Struct: Transformation
 const [
   // constructor
   [, {i: newTransformation}],
@@ -45,9 +45,9 @@ const [
   // [, {i: getFn}],
   // [, {i: getOutput}],
 ] = makeModuleStruct(Transformation)([
-  {l: "input" , r: Value  }, // <- the input is a value (e.g., could be the result of a Transformation itself)
-  {l: "fn"    , r: Value  }, // <- the function is also a value (e.g., could also be result of a transformation, e.g., when currying)
-  {l: "output", r: Dynamic}, // <- the result
+  {l: "input" , r: Value  },
+  {l: "fn"    , r: Value  },
+  {l: "output", r: Dynamic},
 ]);
 
 // Struct: Write