def skolemize(clause: Clause) -> Clause:
# Find all variables in clause
vars = clause.get_variables()
# Map from X,Y,Z,... -> sk0,sk1,sk2,...
subst = {
vars[i]: Constant(f"sk{i}", c_type("thing"))
for i in range(len(vars))
}
# Apply this substitution to create new clause without quantifiers
return clause.substitute(subst), subst
def _instantiate_var_clause(clause: Clause, constant: Constant):
"""
Returns all clauses generated by substituting a `Variable` in `clause` with `constant`.
"""
if isinstance(clause, Body):
suitable_vars = clause.get_variables()
else:
suitable_vars = clause.get_body_variables()
candidates = []
for var in suitable_vars:
candidates.append(clause.substitute({var:constant}))
# if len(candidates) > 0:
# print("Type of each is {}", type(candidates[0]))
return list(set(candidates))