%------------------------------------------------------------------------
% Program that is dynamically stratified but not dynamically stratified
% from left-to-right.  It causes a seg fault.
%
% Both negative and positive simplification is needed (Model = {~p,q}).
%------------------------------------------------------------------------

%:- auto_table.
:- table p/0, q/0.

p :- tnot(q), p.

q :- tnot(q), p.
q :- tnot(p).

%------------------------------------------------------------------------

test :- p, fail.
test :- ( p ->	( tnot(p) -> writeln('p. p is undefined')
		; writeln('p. p is true') )
	; writeln('p. p is false (OK)') ),
        ( q ->  ( tnot(q) -> writeln('p. q is undefined')
		; writeln('p. q is true (OK)') )
	; writeln('p. q is false') ),
	abolish_all_tables, fail.
test :- q, fail.
test :- ( p ->	( tnot(p) -> writeln('q. p is undefined')
		; writeln('q. p is true') )
	; writeln('q. p is false (OK)') ),
        ( q ->  ( tnot(q) -> writeln('q. q is undefined')
		; writeln('q. q is true (OK)') )
	; writeln('q. q is false') ).