(VAR x xs y z )
(RULES 
        le(0, y) -> true
        le(s(x), 0) -> false
        le(s(x), s(y)) -> le(x, y)
        eq(0, 0) -> true
        eq(0, s(y)) -> false
        eq(s(x), 0) -> false
        eq(s(x), s(y)) -> eq(x, y)
        if1(true, x, y, xs) -> min(x, xs)
        if1(false, x, y, xs) -> min(y, xs)
        if2(true, x, y, xs) -> xs
        if2(false, x, y, xs) -> cons(y, del(x, xs))
        minsort(nil) -> nil
        minsort(cons(x, y)) -> cons(min(x, y), minsort(del(min(x, y), cons(x, y))))
        min(x, nil) -> x
        min(x, cons(y, z)) -> if1(le(x, y), x, y, z)
        del(x, nil) -> nil
        del(x, cons(y, z)) -> if2(eq(x, y), x, y, z)
        
)