Warning: CHC: Assertion violation happens here.
Counterexample:

x = 0

Transaction trace:
B.constructor()
B.f(0)
 --> model_checker_contracts_only_one/input.sol:5:3:
  |
5 | 		assert(x > 0);
  | 		^^^^^^^^^^^^^

Warning: CHC: Assertion violation happens here.
Counterexample:

y = 0

Transaction trace:
A.constructor()
A.g(0)
  --> model_checker_contracts_only_one/input.sol:10:3:
   |
10 | 		assert(y > 0);
   | 		^^^^^^^^^^^^^