MAYBE

Problem:
 f(tt(),x) -> f(eq(toOne(x),s(0())),s(x))
 eq(s(x),s(y)) -> eq(x,y)
 eq(0(),0()) -> tt()
 toOne(s(s(x))) -> toOne(s(x))
 toOne(s(0())) -> s(0())

Proof:
 Open