cases.sty version 3.2 2020/03/29
Copyright 1993, 1994, 1995, 2000, 2002, 2020 by Donald Arseneau,
asnd@triumf.ca, Vancouver, Canada.
These macros may be freely transmitted, reproduced, or modified
provided that this notice is left intact. Sub-equation numbering
is based on subeqn.sty by Stephen Gildea; parts are based on LaTeX's
eqnarray by Leslie Lamport and the LaTeX3 team; and some on
amsmath.sty by the American Mathematical Society.
This package provides a LaTeX environment "numcases" to produce
multi-case equations with a separate equation number for each case.
There is also a "subnumcases" environment which numbers each case
with the overall equation number plus a letter [8a, 8b, etc.].