def is_stable(af: ArgumentationFramework, arg_set: frozenset) -> bool:
"""
Verify whether arg_set is a stable extension by
taking the set of arguments which are not attacked by arg_set
and then testing if this set is equal to arg_set
Besnard & Doutre (2004) Checking the acceptability of a set of arguments.
"""
# "the set of arguments which are not attacked by S and then testing if this set is equal to S"
not_attacked_by_arg_set = af.arguments - af.attacked_by(arg_set)
return arg_set == frozenset(not_attacked_by_arg_set)
def is_complete(af: ArgumentationFramework, arg_set: frozenset) -> bool:
"""
Verify whether the arg_set is a complete extension by
Compute the set of arguments defended by arg_set,
the set of arguments not attacked by S and then
to test if their intersection is equal to arg_set.
Besnard & Doutre (2004) Checking the acceptability of a set of arguments.
"""
attacked_by_arg_set = af.attacked_by(arg_set)
defended_by_arg_set = set()
for arg in af.arguments:
attackers = set(af.graph.predecessors(arg))
if attackers.issubset(attacked_by_arg_set):
defended_by_arg_set.add(arg)
not_attacked_by_arg_set = af.arguments - attacked_by_arg_set
intersection = defended_by_arg_set.intersection(
not_attacked_by_arg_set)
return arg_set == frozenset(intersection)