anchor.diff:      | Tuple3 of TypeAlg * TypeAlg * TypeAlg
   
   /// Type Algebra pretty-printer
  -let rec toString (atype : TypeAlg) =
  -    match atype with
  +let rec toString (tAlg : TypeAlg) =
  +    match tAlg with
       | Unit -> "unit"
       | Bool -> "bool"
       | Int32 -> "int"
  
positive.code: type IPredicate =
      abstract Invoke<'T> : value:'T -> bool
  
  /// Type Algebra implementation
  type TypeAlg =
      | Unit
      | Bool
  
negative.code:     | Tuple3 (t1,t2,t3) -> sprintf "(%s * %s * %s)" (toString t1) (toString t2) (toString t3)
  
  /// Converts a TypeAlg representation to its corresponding System.Type
  let rec toSysType (tAlg : TypeAlg) : Type =
      match tAlg with
      | Unit -> typeof<unit>
      | Bool -> typeof<bool>
      | Int32 -> typeof<int>
  