diff --git a/main-settings/src/main/scala/sbt/InputTask.scala b/main-settings/src/main/scala/sbt/InputTask.scala
index 720b31d1c..3f8331964 100644
--- a/main-settings/src/main/scala/sbt/InputTask.scala
+++ b/main-settings/src/main/scala/sbt/InputTask.scala
@@ -10,7 +10,7 @@ package sbt
 import sbt.internal.util.complete.Parser
 import Def.{ Initialize, ScopedKey }
 import std.TaskExtra._
-import sbt.internal.util.{ ~>, AttributeKey, Types }
+import sbt.internal.util.{ AttributeKey, Types }
 import sbt.internal.util.Types._
 import sbt.internal.util.Util._
 import sbt.util.Applicative
diff --git a/main-settings/src/main/scala/sbt/Structure.scala b/main-settings/src/main/scala/sbt/Structure.scala
index 69304e9ba..f01046487 100644
--- a/main-settings/src/main/scala/sbt/Structure.scala
+++ b/main-settings/src/main/scala/sbt/Structure.scala
@@ -10,7 +10,7 @@ package sbt
 import scala.annotation.targetName
 
 import sbt.internal.util.Types.*
-import sbt.internal.util.{ ~>, AttributeKey, Settings, SourcePosition }
+import sbt.internal.util.{ AttributeKey, Settings, SourcePosition }
 import sbt.internal.util.TupleMapExtension.*
 import sbt.util.OptJsonWriter
 import sbt.ConcurrentRestrictions.Tag
diff --git a/main-settings/src/main/scala/sbt/std/TaskMacro.scala b/main-settings/src/main/scala/sbt/std/TaskMacro.scala
index 29677d2e1..7e02b48e1 100644
--- a/main-settings/src/main/scala/sbt/std/TaskMacro.scala
+++ b/main-settings/src/main/scala/sbt/std/TaskMacro.scala
@@ -21,7 +21,7 @@ import sbt.internal.util.appmacro.{
   // MonadInstance
 }
 // import Instance.Transform
-import sbt.internal.util.{ LinePosition, NoPosition, SourcePosition, ~> }
+import sbt.internal.util.{ LinePosition, NoPosition, SourcePosition }
 
 import language.experimental.macros
 import scala.annotation.tailrec
diff --git a/main/src/main/scala/sbt/ProjectExtra.scala b/main/src/main/scala/sbt/ProjectExtra.scala
index a800e0c6f..f8d6fba00 100755
--- a/main/src/main/scala/sbt/ProjectExtra.scala
+++ b/main/src/main/scala/sbt/ProjectExtra.scala
@@ -46,8 +46,8 @@ import sbt.internal.{
   SettingCompletions,
   SessionSettings
 }
-import sbt.internal.util.{ AttributeKey, AttributeMap, Dag, Relation, Settings, ~> }
-import sbt.internal.util.Types.const // , idFun }
+import sbt.internal.util.{ AttributeKey, AttributeMap, Dag, Relation, Settings }
+import sbt.internal.util.Types.const
 import sbt.internal.util.complete.DefaultParsers
 import sbt.internal.server.ServerHandler
 import sbt.librarymanagement.Configuration
diff --git a/main/src/main/scala/sbt/internal/Load.scala b/main/src/main/scala/sbt/internal/Load.scala
index e44079a04..3178b5ae2 100755
--- a/main/src/main/scala/sbt/internal/Load.scala
+++ b/main/src/main/scala/sbt/internal/Load.scala
@@ -22,7 +22,7 @@ import sbt.internal.inc.{ MappedFileConverter, ScalaInstance, ZincLmUtil, ZincUt
 import sbt.internal.server.BuildServerEvalReporter
 import sbt.internal.util.Attributed.data
 import sbt.internal.util.Types.const
-import sbt.internal.util.{ Attributed, Settings, ~> }
+import sbt.internal.util.{ Attributed, Settings }
 import sbt.io.{ GlobFilter, IO, Path }
 import sbt.librarymanagement.ivy.{ InlineIvyConfiguration, IvyDependencyResolution, IvyPaths }
 import sbt.librarymanagement.{ Configuration, Configurations, Resolver }
diff --git a/sbt-app/src/main/scala/sbt/Import.scala b/sbt-app/src/main/scala/sbt/Import.scala
index 41eb0ba86..258960075 100644
--- a/sbt-app/src/main/scala/sbt/Import.scala
+++ b/sbt-app/src/main/scala/sbt/Import.scala
@@ -206,7 +206,7 @@ trait Import {
   type UnprintableException = sbt.internal.util.UnprintableException
   val Util = sbt.internal.util.Util
   // val ~> = sbt.internal.util.~>
-  type ~>[-K[_], +V[_]] = sbt.internal.util.~>[K, V]
+  // type ~>[-K[_], +V[_]] = sbt.internal.util.~>[K, V]
 
   // sbt.internal.util.complete
   object complete {
diff --git a/tasks-standard/src/main/scala/sbt/Task.scala b/tasks-standard/src/main/scala/sbt/Task.scala
index 5a79c5bd6..0e0833db8 100644
--- a/tasks-standard/src/main/scala/sbt/Task.scala
+++ b/tasks-standard/src/main/scala/sbt/Task.scala
@@ -9,7 +9,7 @@ package sbt
 
 import sbt.internal.Action
 import sbt.internal.util.Types.const
-import sbt.internal.util.{ ~>, AttributeKey, AttributeMap }
+import sbt.internal.util.{ AttributeKey, AttributeMap }
 import ConcurrentRestrictions.{ Tag, TagMap, tagsKey }
 import sbt.util.Monad
 
diff --git a/tasks-standard/src/main/scala/sbt/std/Transform.scala b/tasks-standard/src/main/scala/sbt/std/Transform.scala
index f3e24b18e..601096b3a 100644
--- a/tasks-standard/src/main/scala/sbt/std/Transform.scala
+++ b/tasks-standard/src/main/scala/sbt/std/Transform.scala
@@ -9,7 +9,7 @@ package sbt
 package std
 
 import sbt.internal.Action
-import sbt.internal.util.{ ~>, DelegatingPMap, RMap }
+import sbt.internal.util.{ DelegatingPMap, RMap }
 import sbt.internal.util.TupleMapExtension.*
 import TaskExtra.{ all, existToAny }
 import sbt.internal.util.Types.*
diff --git a/tasks/src/main/scala/sbt/Execute.scala b/tasks/src/main/scala/sbt/Execute.scala
index 963819f05..e17142568 100644
--- a/tasks/src/main/scala/sbt/Execute.scala
+++ b/tasks/src/main/scala/sbt/Execute.scala
@@ -10,7 +10,7 @@ package sbt
 import java.util.concurrent.ExecutionException
 
 import sbt.internal.util.ErrorHandling.wideConvert
-import sbt.internal.util.{ DelegatingPMap, IDSet, PMap, RMap, ~> }
+import sbt.internal.util.{ DelegatingPMap, IDSet, PMap, RMap }
 import sbt.internal.util.Types.const
 import sbt.internal.util.Util.nilSeq
 
diff --git a/tasks/src/main/scala/sbt/Result.scala b/tasks/src/main/scala/sbt/Result.scala
index b454e3f3c..3b5191b98 100644
--- a/tasks/src/main/scala/sbt/Result.scala
+++ b/tasks/src/main/scala/sbt/Result.scala
@@ -7,8 +7,6 @@
 
 package sbt
 
-import sbt.internal.util.~>
-
 // used instead of Either[Incomplete, T] for type inference
 
 /** Result of completely evaluating a task. */
diff --git a/util-collection/src/main/scala/sbt/internal/util/PMap.scala b/util-collection/src/main/scala/sbt/internal/util/PMap.scala
index 1d94e06d5..1b40355bb 100644
--- a/util-collection/src/main/scala/sbt/internal/util/PMap.scala
+++ b/util-collection/src/main/scala/sbt/internal/util/PMap.scala
@@ -26,15 +26,14 @@ trait RMap[K[_], V[_]] {
   sealed case class TPair[T](key: K[T], value: V[T])
 }
 
-trait IMap[K[_], V[_]] extends (K ~> V) with RMap[K, V] {
+trait IMap[K[_], V[_]] extends RMap[K, V] {
   def put[T](k: K[T], v: V[T]): IMap[K, V]
   def remove[T](k: K[T]): IMap[K, V]
   def mapValue[T](k: K[T], init: V[T], f: V[T] => V[T]): IMap[K, V]
   def mapValues[V2[_]](f: [A] => V[A] => V2[A]): IMap[K, V2]
-  def mapSeparate[VL[_], VR[_]](f: V ~> λ[T => Either[VL[T], VR[T]]]): (IMap[K, VL], IMap[K, VR])
 }
 
-trait PMap[K[_], V[_]] extends (K ~> V) with RMap[K, V] {
+trait PMap[K[_], V[_]] extends RMap[K, V] {
   def update[T](k: K[T], v: V[T]): Unit
   def remove[T](k: K[T]): Option[V[T]]
   def getOrUpdate[T](k: K[T], make: => V[T]): V[T]
@@ -80,21 +79,6 @@ object IMap {
         k -> f(v.asInstanceOf[V[Any]])
       }.toArray: _*))
 
-    def mapSeparate[VL[_], VR[_]](f: V ~> λ[T => Either[VL[T], VR[T]]]) = {
-      val left = new java.util.concurrent.ConcurrentHashMap[K[Any], VL[Any]]
-      val right = new java.util.concurrent.ConcurrentHashMap[K[Any], VR[Any]]
-      Par(backing.toVector).foreach { case (k, v) =>
-        f(v.asInstanceOf[V[Any]]) match {
-          case Left(l)  => left.put(k, l)
-          case Right(r) => right.put(k, r)
-        }
-      }
-      (
-        new IMap0[K, VL](new WrappedMap(left.asInstanceOf)),
-        new IMap0[K, VR](new WrappedMap(right.asInstanceOf))
-      )
-    }
-
     def toSeq = backing.toSeq.asInstanceOf[Seq[(K[Any], V[Any])]]
     def keys = backing.keys.asInstanceOf[Iterable[K[Any]]]
     def values = backing.values.asInstanceOf[Iterable[V[Any]]]
diff --git a/util-collection/src/main/scala/sbt/internal/util/TypeFunctions.scala b/util-collection/src/main/scala/sbt/internal/util/TypeFunctions.scala
index 78a46a933..c35f5cb01 100644
--- a/util-collection/src/main/scala/sbt/internal/util/TypeFunctions.scala
+++ b/util-collection/src/main/scala/sbt/internal/util/TypeFunctions.scala
@@ -11,7 +11,6 @@ trait TypeFunctions:
   type Id[X] = X
   type NothingK[X] = Nothing
 
-  sealed trait ∙[A[_], B[_]] { type l[T] = A[B[T]] }
   private type AnyLeft[A] = Left[A, Nothing]
   private type AnyRight[A] = Right[Nothing, A]
   final val left: [A] => A => AnyLeft[A] = [A] => (a: A) => Left(a)
@@ -56,16 +55,6 @@ object TypeFunctions extends TypeFunctions:
 end TypeFunctions
  */
 
-trait ~>[-F1[_], +F2[_]] { outer =>
-  def apply[A](f1: F1[A]): F2[A]
-  // directly on ~> because of type inference limitations
-  final def ∙[F3[_]](g: F3 ~> F1): F3 ~> F2 = new ~>[F3, F2] {
-    override def apply[A](f3: F3[A]) = outer.apply(g(f3))
-  }
-  final def ∙[C, D](g: C => D)(implicit ev: D <:< F1[D]): C => F2[D] = i => apply(ev(g(i)))
-  lazy val fn: [A] => F1[A] => F2[A] = [A] => (f1: F1[A]) => outer.apply[A](f1)
-}
-
 /*
 object ~> {
   import TypeFunctions._