anchor.diff:  
   let mkBindThatAddr g m ty thataddrv thatv thate expr =
       if isStructTy g ty then
  -        mkCompGenLet m thataddrv (mkValAddr m (mkLocalValRef thatv))  expr
  +        // let thataddrv = &thatv
  +        mkCompGenLet m thataddrv (mkValAddr m (mkLocalValRef thatv))  expr  
       else
  -        mkCompGenLet m thataddrv thate expr
  -
  -let mkBindThatAddrIfNeeded g m ty thataddrvOpt thatv thate expr =
  +        // let thataddrv = that
  +        mkCompGenLet m thataddrv thate expr 
  +
  +let mkBindThatAddrIfNeeded m thataddrvOpt thatv expr =
       match thataddrvOpt with 
       | None -> expr
       | Some thataddrv ->
  +        // let thataddrv = &thatv
           mkCompGenLet m thataddrv (mkValAddr m (mkLocalValRef thatv))  expr
   
   let mkDerefThis g m (thisv: Val) thise =
  
positive.code:     let fields = tycon.AllInstanceFieldsAsList
      let tinst,ty = mkMinimalTy g tcref
      let tcv,tce = mkCompGenLocal m "objTemp" ty    // let tcv = thate
      let thataddrv,thataddre = mkThatAddrLocal g m tce ty      // let thataddrv = &tcv, if a struct
      
      let mkTest (fspec:RecdField) = 
          let fty = fspec.FormalType 
  
negative.code:                tagsEqTested) 
  
      let expr = if tycon.IsStructOrEnumTycon then expr else mkBindNullComparison g m thise thatcaste expr
      let expr = mkBindThatAddrIfNeeded m thataddrvOpt tcv expr
      let expr = mkCompGenLet m tcv thatcaste expr
      expr
      
  