cnf(a_not_equal_to_additive_identity_2,negated_conjecture, ( ~ equalish(a,additive_identity) )). cnf(less_or_equal_3,negated_conjecture, ( less_or_equal(a,additive_identity) )). cnf(not_less_or_equal_4,negated_conjecture, ( ~ less_or_equal(multiplicative_inverse(a),additive_identity) )).