mfenced: open, close, separators 1 2
menclose: notation menclose
mfrac: bevelled, linethickness a b
mfrac: numalign 1 234
mfrac: denomalign 123 4
mmultiscripts: subscriptshift, superscriptshift a b c e f
msubsup: subscriptshift, superscriptshift a b c
msub: subscriptshift a b
msup: superscriptshift a b