Warning: CHC: Division by zero happens here. Counterexample: arr = [] a = 0x0 x = 0 Transaction trace: test.constructor() State: arr = [] test.f(0x0, 1) --> model_checker_targets_default_all_engines/input.sol:9:3: | 9 | 2 / x; | ^^^^^ Warning: CHC: Assertion violation happens here. Counterexample: arr = [] a = 0x0 x = 0 Transaction trace: test.constructor() State: arr = [] test.f(0x0, 1) --> model_checker_targets_default_all_engines/input.sol:11:3: | 11 | assert(x > 0); | ^^^^^^^^^^^^^ Warning: CHC: Empty array "pop" happens here. Counterexample: arr = [] a = 0x0 x = 0 Transaction trace: test.constructor() State: arr = [] test.f(0x0, 1) --> model_checker_targets_default_all_engines/input.sol:12:3: | 12 | arr.pop(); | ^^^^^^^^^ Warning: CHC: Out of bounds access happens here. Counterexample: arr = [] a = 0x0 x = 0 Transaction trace: test.constructor() State: arr = [] test.f(0x0, 1) --> model_checker_targets_default_all_engines/input.sol:13:3: | 13 | arr[x]; | ^^^^^^ Warning: BMC: Condition is always true. --> model_checker_targets_default_all_engines/input.sol:6:11: | 6 | require(x >= 0); | ^^^^^^ Note: Callstack: Warning: BMC: Insufficient funds happens here. --> model_checker_targets_default_all_engines/input.sol:10:3: | 10 | a.transfer(x); | ^^^^^^^^^^^^^ Note: Counterexample: a = 0 x = 0 Note: Callstack: Note: