more about SEQ

[David Chapman <Zvona at MIT-AI>]

Actually, SEQ does not avoid introducing temporary names at all; it just
defines a default temporary name * (an accumulator) and saves you
having to think of a gensym.

An alternative I tried as part of a since-flushed feature of the
Programmer's Apprentice was to edit data-flow diagrams directly: (G x x)
is just   

	    ---
           | x |
            -o-
	   /   \
	--o-----o--
	|    G    |
	-----------

Some other Programmer's Apprentice software would convert between this
representation and lisp.  Of course big box/arrow diagrams got unusable
pretty fast.