cases.sty version 3.1 2020/03/10

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.].