This package allows you to check whether a string is contained
within another set of strings, and perform an action if it is
not. This is done by using the allfalse environment and passing
in a string and an action to be performed if the string is not
contained in the set. Then, passing in a string to the \orcheck
macro inside the respective allfalse environment adds that to
the set of strings. This package does not work with the LuaTeX
engine.
