anchor.diff:          /// <summary>
           ///     The proof gave an odd result.
           /// </summary>
  -        | Unknown
  +        | Unknown of reason: string
   
       /// <summary>
       ///     A MuZ3 model.
  
positive.code:     /// Pretty-prints a MuSat.
      let printMuSat =
          function
          | MuSat.Sat ex -> commaSep [ String "sat" ; printZ3Exp ex ]
          | MuSat.Unsat ex -> commaSep [ String "unsat" ; printZ3Exp ex ]
          | MuSat.Unknown -> String "?"
      
      /// Pretty-prints a MuModel.
      let printMuModel { Assertions = ts ; Rules = rs ; FuncDecls = fdm } =
  
negative.code:                      MuSat.Sat (fixedpoint.GetAnswer ())
                   | Z3.Status.UNSATISFIABLE ->
                       MuSat.Unsat (fixedpoint.GetAnswer ())
                   | Z3.Status.UNKNOWN ->
                       MuSat.Unknown (fixedpoint.GetReasonUnknown ())
                   | _ -> MuSat.Unknown "query result out of bounds")
              fm
  
  
  