FBoundedSimplification.scala

// does this work out?

trait Txn[S <: Sys] {
   def newVar[A](init: A): S#Vr[A]
}

trait Var[Tx, A] {
   def get(implicit tx: Tx): A
   def set(value: A)(implicit tx: Tx): Unit
}

trait Sys {
  type S = this.type // ! yes ??
  type Tx <: Txn[S]
  type Vr[A] <: Var[S#Tx, A]
}

// nope...

trait Txn[S <: Sys] {
   def newVar[A](init: A): S#Vr[A]
}

trait Var[Tx, A] {
   def get(implicit tx: Tx): A
   def set(value: A)(implicit tx: Tx): Unit
}

trait Identifier[Tx] {
   def dispose()(implicit tx: Tx): Unit
}

trait Sys {
  type S = this.type
  type Tx <: Txn[S]
  type Vr[A] <: Var[S#Tx, A]
  type ID <: Identifier[S#Tx]
}

trait Identifiable[+ID] { def id: ID }

trait Test[S <: Sys] extends Identifiable[S#ID] {
   def dispose()(implicit tx: S#Tx) {
      id.dispose() // !Fail!
   }
}