def eval(env, a, b): return base.number(a.eval(env) + b.eval(env))
def with_b(b_val): return base.Bounce(k, base.number(a_val / b_val))
def eval(env, v): return base.number(math.floor(v.eval(env).value))
def with_val(val): return base.Bounce(k, base.number(math.floor(val.value)))
def eval(env, v): return base.number(math.ceil(v.eval(env).value))