MAYBE

Problem:
 strict:
  half(0()) -> 0()
  half(s(0())) -> 0()
  half(s(s(x))) -> s(half(x))
  lastbit(0()) -> 0()
  lastbit(s(0())) -> s(0())
  lastbit(s(s(x))) -> lastbit(x)
  conv(0()) -> cons(nil(),0())
  conv(s(x)) -> cons(conv(half(s(x))),lastbit(s(x)))
 weak:
  rand(x) -> x
  rand(x) -> rand(s(x))

Proof:
 Open