Warning: CHC: Underflow (resulting value less than 0) happens here.
Counterexample:
arr = []
a = 0
x = 0

Transaction trace:
test.constructor()
State: arr = []
test.f(0, 0)
 --> model_checker_targets_all/input.sol:8:3:
  |
8 | 		--x;
  | 		^^^

Warning: CHC: Overflow (resulting value larger than 2**256 - 1) happens here.
Counterexample:
arr = []
a = 0
x = 1

Transaction trace:
test.constructor()
State: arr = []
test.f(0, 2)
 --> model_checker_targets_all/input.sol:9:3:
  |
9 | 		x + type(uint).max;
  | 		^^^^^^^^^^^^^^^^^^

Warning: CHC: Division by zero happens here.
Counterexample:
arr = []
a = 0
x = 0

Transaction trace:
test.constructor()
State: arr = []
test.f(0, 1)
  --> model_checker_targets_all/input.sol:10:3:
   |
10 | 		2 / x;
   | 		^^^^^

Warning: CHC: Assertion violation happens here.
Counterexample:
arr = []
a = 0
x = 0

Transaction trace:
test.constructor()
State: arr = []
test.f(0, 1)
  --> model_checker_targets_all/input.sol:12:3:
   |
12 | 		assert(x > 0);
   | 		^^^^^^^^^^^^^

Warning: CHC: Empty array "pop" happens here.
Counterexample:
arr = []
a = 0
x = 0

Transaction trace:
test.constructor()
State: arr = []
test.f(0, 1)
  --> model_checker_targets_all/input.sol:13:3:
   |
13 | 		arr.pop();
   | 		^^^^^^^^^

Warning: BMC: Condition is always true.
 --> model_checker_targets_all/input.sol:7:11:
  |
7 | 		require(x >= 0);
  | 		        ^^^^^^
Note: Callstack:

Warning: BMC: Insufficient funds happens here.
  --> model_checker_targets_all/input.sol:11:3:
   |
11 | 		a.transfer(x);
   | 		^^^^^^^^^^^^^
Note: Counterexample:
  a = 0
  x = 0

Note: Callstack:
Note: