function {:existential true} {:inline} b1(x: bool, y: bool) : bool
{
  (y || x) && (!x || !y)
}
function {:existential true} {:absdomain "Intervals"} {:inline} b3(x: int) : bool
{
  x >= 0 && x <= 0
}

Boogie program verifier finished with 1 verified, 0 errors