function {:existential true} {:inline} b0(x: bool, y: bool) : bool
{
  x && !y
}
function {:existential true} {:inline} b1(x: bool, y: bool) : bool
{
  (y || x) && (!x || !y)
}
function {:existential true} {:inline} b2(x: bool, y: bool) : bool
{
  x && !y
}

Boogie program verifier finished with 1 verified, 0 errors