// AssertBy.dfy

method M0(x: int, y: int)
{
  assert x == 6;
  assert y == 8;
}

method M1(x: int, y: int)
{
  assert x == 6 by {
    assume x == 6;
    assume y == 8;
  }
  assert y == 8;
}
AssertBy.dfy(6,11): Error: assertion might not hold
AssertBy.dfy(7,11): Error: assertion might not hold
AssertBy.dfy(16,11): Error: assertion might not hold

Dafny program verifier finished with 0 verified, 3 errors
