% Copyright (C) 2013 Peter Schueller <schueller.p@gmail.com>

%schema1.
schema2 :- not schema1.

nom(g1,n1,pillar).
nom(g1,n2,i).
mod(g1,n3,between).
nom(g1,n4,stage).
act(g1,n7,see) :- schema1.
act(g1,n7,see_around) :- schema2.
nom(g1,n8,entity).

dep(g1,d1,n1,n3,@set((subj))).
dep(g1,d2,n2,n3,@set(obj)).
dep(g1,d3,n4,n3,@set(obj2)).
dep(g1,d5,n2,n7,@set(cannot)).
dep(g1,d7,n8,n7,@set(obj)).
dep(g1,d8,d1,d5,@set((meta,nonvolatile_result))).

% A34 
print("There is a pillar between me and the stage, and I can't see it.") :- schema1.
print("There is a pillar between me and the stage, and I can't see around it.") :- schema2.

% either n1=n8 or n4=n8
required_equivalence(g1,eq1,n1,n8).
required_equivalence(g1,eq1,n4,n8).

correct_result(g1,n4,n8) :- schema1.
correct_result(g1,n1,n8) :- schema2.