If all works of art evoke intense feelings, and this sculpture is a work of art, then it follows that this sculpture evokes intense feelings  But this sculpture does not evoke intense feelings at all
So either this sculpture is not a work of art, or not all works of art evoke intense feelings
If all classes are canceled today, then it follows that today is a holiday and the library is closed. But today is not a holiday. So some classes are not canceled, or the library is open.