MAYBE

Problem:
 while(true(),x,y) -> cond(gt(x,0()),x,y)
 cond(true(),s(x),y) -> while(gt(y,0()),x,y)
 cond(false(),x,y) -> while(gt(s(y),0()),s(y),s(y))
 gt(s(x),0()) -> true()
 gt(0(),x) -> false()
 gt(s(x),s(y)) -> gt(x,y)

Proof:
 Open