I have a question about the applyrule function. exprsnsinzAcosz Bcosxcosz Ccosx와 같은 식이 있는데, coszsinz를 sinzsinz 형식으로 표현하고 싶습니다. However, when I use the applyrule as exprsn applyrulesinzcoszsinzsinz, exprsn it returns the same expression.