Works In Yap

root@ubuntu:/mnt/gggg/logicmoo_workspace/pack/prologmud_samples/prolog/prologmud_sample_games# yap
% Restoring file /usr/lib/Yap/startup.yss
YAP 6.2.2 (x86_64-linux): Wed Jul 15 05:25:26 UTC 2015
   ?-  assert(predZZ(1,a)),  assert(predZZ(_,b)).
yes
   ?- predZZ(1,a).
yes
   ?-


GNU Prolog 1.3.0
By Daniel Diaz
Copyright (C) 1999-2007 Daniel Diaz
| ?- assert(predZZ(1,a)),  assert(predZZ(_,b)).
uncaught exception: error(existence_error(procedure,assert/1),top_level/0)
| ?-  assertz(predZZ(1,a)).

yes
| ?- assertz(predZZ(_,b)).

yes
| ?- predZZ(1,a).

true ? ;

no
| ?-