Theorems and similar environments
All the theorem creating commands in LATEX will work correctly and can be used in Neptune.
However, there are three more commands to create theorem like environments:
\newdefinition: creates a theorem like environment; the key difference is that the statement font is upright, unlike italic in the standard theorem. All the options in the theorem will work here too.
\newproof: creates a Proof environment with no counters and with upright font.
\newitproof: is similar to
\newproof, the only difference being the font is in italic shape.