Implementation of MAP, SOME, etc

[Jon White <JLW@SU-AI.ARPA>]

Surely the CLM doesn't suggest that the implementation of these functions
must call the LENGTH function -- whereas it may not hurt to do so for what
I'd call "index access" datatypes, there are many reasons for not doing so
on lists.  The phrase I see in the manual is "... if the end of a sequence
is reached ...", and this doesn't say how one determines that the end
is reached.  But the docmentation of ENDP suggests that it is the preferred
way to answer the question for lists.

-- JonL --