_From @ClaudeZou on August 14, 2015 18:53_ `L_n(x) -> \Laguerre{n}@{x}` `L_n^{(\alpha)}(x) -> \Laguerre{n}[\alpha]@{x}` This is an example of a macro with an optional parameter. _Copied from original issue: DRMF/texvcjs#20_