// S : tags   c sym todo  $TAGS
// S : expect --result valid
// S : cc     -o test.bc  $CC_OPT $file
// S : verify --symbolic --solver $solver --sequential -o nofail:malloc -o ignore:control $V_OPT test.bc

// N : V          : CC_OPT        : V_OPT : TAGS : RESULT
// V : big.100000 : -DSIZE=100000 :       : big  : valid
// V : big.10000  : -DSIZE=10000  :       : big  : valid
// V : small.100  : -DSIZE=100    :       : big  : valid
// V : small.10   : -DSIZE=10     :       :      : valid
// V : big.1000   : -DSIZE=1000   :       : big  : valid

/* Benchmark used to verify Chimdyalwar, Bharti, et al. "VeriAbs: Verification by abstraction (competition contribution)."
International Conference on Tools and Algorithms for the Construction and Analysis of Systems. Springer, Berlin, Heidelberg, 2017.*/

extern void __VERIFIER_error() __attribute__ ((__noreturn__));
extern void __VERIFIER_assume(int);
void __VERIFIER_assert(int cond)
{
  if (!(cond)) {
    ERROR: __VERIFIER_error();
  }
  return;
}

unsigned int __VERIFIER_nondet_uint();

int main()
{
  unsigned int array[SIZE];
  unsigned int index1;
  unsigned int index2;
  unsigned int loop_entered = 0;

  index1 =  __VERIFIER_nondet_uint();
  __VERIFIER_assume(index1 < SIZE);
  index2 =  __VERIFIER_nondet_uint();
  __VERIFIER_assume(index2 < SIZE);

  while (index1 < index2) {
    __VERIFIER_assert((index1 < SIZE) && (index2 < SIZE));
    __VERIFIER_assume(array[index1] == array[index2]);
    index1++;
    index2--;
    loop_entered = 1;
  }

  if (loop_entered) {
    while (index2 < index1) {
      __VERIFIER_assert(array[index1] == array[index2]);
      index2++;
      index1--;
    }
  }

}