m4 complains about undocumented, unimplemented functions

[Arnold Robbins]

This happened to me on vax running 4.1BSD, but I would be willing to bet it
will happen with any version of m4.

I was using m4 to process some text (/lib/cpp wasn't working right for some
reason), and the text had the word `shift' in it.  M4 told me "shift: not
implemented yet".  I just put it in m4 quotes (`'), and it worked fine, but
I really think it should just ignore what isn't documented or implemented.
I checked some V7 source, and this goes all the way back to there.  I can't
even blame it on Berkeley!
-- 
Arnold Robbins
CSNET:	arnold at gatech	ARPA:	arnold%gatech.csnet at csnet-relay.arpa
UUCP:	{ akgua, allegra, hplabs, ihnp4, seismo, ut-sally }!gatech!arnold

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