(COMMENT harder variant of AG01 4.24, where int(x,y) computes the list [x,x+1,...,y]) (VAR x y) (RULES le(0,y) -> true le(s(x),0) -> false le(s(x),s(y)) -> le(x,y) int(x,y) -> if(le(x,y),x,y) if(true,x,y) -> cons(x,int(s(x),y)) if(false,x,y) -> nil )