Byrd - Saveit

agg_all(min(X), Goal, Min) :-
  State = state(X),  % X looks lovely here - really its just a hack so we don't reserve a new slot on the stack like using _ would. we could have easily written:  State = state(Goal),
   (  call(Goal),
     (
      % savit
      (nb_setarg(1, State, X),fail)
  ;

     % 2nd - Nth
     ( arg(1, State, M0),
      M is min(M0,X),
      nb_setarg(1, State, M),
      fail))
   ;  arg(1, State, Min),
      nonvar(Min)
   ).