anchor.diff:  (* ------------------------------------------------------------------------- *)
   (* Eliminate select terms from a goal.                                       *)
   (* ------------------------------------------------------------------------- *)
  +
   /// Eliminate select terms from a goal.
   let SELECT_ELIM_TAC = 
       let SELECT_ELIM_CONV = 
  
positive.code: (* ------------------------------------------------------------------------- *)
  (* Pre-simplification.                                                       *)
  (* ------------------------------------------------------------------------- *)
  /// Applies basic propositional simplications and some miniscoping.
  let PRESIMP_CONV = 
  
negative.code: 
  open FSharp.Compatibility.OCaml
  open FSharp.Compatibility.OCaml.Num
  
  open ExtCore.Control
  
  open NHol
  open lib
  