/*
 * Cours "Sémantique et Application à la Vérification de programmes"
 *
 * Josselin Giet 2021
 * Ecole normale supérieure, Paris, France / CNRS / INRIA
 */

void main(){
  int i = 0;
  if(brand){ goto L1; }
  L0: // performing a widening here loose all information
    goto LF;
  L1:
    if(brand) { i += 1; } else { i -= 1; } // i in [-1; 1]
    goto L0;

  LF:
    assert(i <= 1);
    assert(i >= -1);
}