The math delimiters for floor and ceiling functions (\lfloor, \rfloor, \lceil, \rceil) work with the automatic scaling commands (\left and \right) but vanish with the manual scaling commands (\big, \Big, \bigg, \Bigg, \bigl, \Bigl, \biggl, \Biggl, \bigr, \Bigr, \biggr, \Biggr). Do I use the right commands? Or could the developers fix that?

Thank you in advance.

Maggyero