anchor.diff:      match !_z3version with
       | Some version -> version
       | None ->
  -        let _, out, _ = BU.run_proc (Options.z3_exe()) "-version" "" in
  +        let _, out, _ = BU.run_proc (z3_exe()) "-version" "" in
           let out =
               match splitlines out with
               | x :: _ when starts_with x prefix -> begin
  
positive.code: type z3version =
  | Z3V_Unknown of string
  | Z3V of int * int * int
  
  let z3version_as_string = function
      | Z3V_Unknown s -> BU.format1 "unknown version: %s" s
  
negative.code:     if Options.n_cores() = 1 then
          ask_1_core core label_messages qry cb
      else
          ask_n_cores core label_messages qry scope cb
  