Model validation fails: failed to verify: (or a (not (and a b)))

[wintered]

Hi,
For this formula:

(declare-fun a () Bool)
(declare-fun b () Bool)
(assert (or (not (and a b)) a))
(check-sat)

failed to verify: (or a (not (and a b)))
evaluated to (or a (not (and a b)))
(params keep_cardinality_constraints true pb.solver solver xor_solver false)
sat

OS: Ubuntu 18.04
Commit: 6b0e599

[wintered]

Another variant of the same error

(declare-fun a () Bool)
(declare-fun b () Bool)
(assert (not (and b (not (or a b)))))
(check-sat)

failed to verify: (not (and b (not (or a b))))
evaluated to (not (and b (not (or a b))))
(params keep_cardinality_constraints true pb.solver solver xor_solver false)
sat