M-label definition

[Paul Hoffman]

At 4:59 PM -0700 4/7/09, Lisa Dusseault wrote:
>I'm not certain a new term needs to be introduced.  If we're talking
>about a string that is invalid as a label, giving it that term seems
>to legitimize it.  If we're talking about a string that may or may not
>be valid, that's just "a string"
>

Good catch. John's second option was:

>        "An M-label is a string that can be mapped into a
>        [valid] U-label.  It may be a U-label, since those
>        trivially map into themselves.  The category of U-label
>        is a proper subset of the category of M-label." (Mark
>        and others).

When I supported it, I was thinking of it as "...a valid U-label", that is, without the "valid" being optional.