Where did <somefunction>p come from?

[hall@research.att.com (Bob Hall)]

    From: tcasasent@kbsi.com (Tod "Mughi" Casasent)
    Date: Fri, 27 May 1994 16:19:20 GMT

    Why does LISP use a "p" at the end of the function?

I believe the "p" is for "predicate" to indicate that the return value
is a Boolean (T or NIL).

If you are asking why do this at all, it is a matter of style to use such
a mnemonic to indicate this information.  If you are asking why do this
instead of a "?" or something else, it may have to do with limitations of
old input devices.

-- Bob