%%%%% DEFEAT %%%%% % formula for defeater check checkDefeat(imp(XF,neg(YF))) :- selected1(X), selected2(Y), as(X,claim,XF), support(Y,YF). subformula(X) :- checkDefeat(X). % guess variable assignments for defeat check true(defeat,X) | false(defeat,X) :- atom(X). attack :- ismodel(defeat,X), checkDefeat(X).