I vote for bang.  I think that it's important to reserve
special-character prefixes and suffixes for the use of application
programmers, so I'm against ``using up'' the whorl character just to
provide a visual reminder of a procedure's linear-update effect.  And I
agree with Olin that adding the digit-one character is ugly, not to mention
arbitrary.

--
======  John David Stone - Lecturer in Computer Science and Philosophy  =====
==============  Manager of the Mathematics Local-Area Network  ==============
==============  Grinnell College - Grinnell, Iowa 50112 - USA  ==============
========  xxxxxx@cs.grinnell.edu - http://www.cs.grinnell.edu/~stone/  =======