Martin Schoenert writes:
#The general description is in the section "Dispatchers". The sections
#for the dispatchers contain paragraphs like the following
#
# 'Orbit' calls \\
# '<G>.operations.Orbit( <G>, <d>, <operation> )' \\
# and returns the value. Note that the third argument is not optional for
# functions called this way.
#
#But this is not done consistently in the manual, so if you find a section
#without such a paragraph, it doesn't mean that the function is not a
#dispatcher.
#
#In section "Function Calls" you will find
#
# An exception again occurs if the function has only one formal argument
# with the name 'arg'. In this case the values of all the actual arguments
# are stored in a list and this list is assigned to the new variable
# corresponding to the formal argument 'arg'.
#

Thanks for these references and your hepl about dispatchers in general.
Perhaps the index in the GAP manual should be updated so as to point to
these things?

On another note, a long while ago I wrote a Sublist routine to give all in
the sublists in a list and afterwards I discovered that there is a
SubList function in the GAP libraries. Mine is significantly faster on
large lists; if you want me to send you a copy let me know (the difference is
that the GAP version uses recursion whereas mine uses boolean arithmetic).

Regards,
        Andrew