Implies and Equivalent now map numbers to (True, False)

Currently, Implies(0,0) returns Implies(0,0) instead of True.
Classes like And, Not and Or convert integers to True/False, but classes like Implies and Equivalent do not. simplify_logic depends on 0, 1 being treated as False, True on substituion
Hence, the said classes have been modified to map numbers to (True, false)