Proposed KMP/RWK cond

[Greenberg at MIT-Multics]

 A better understanding of my objection to this construct is that
it seems totaaly limited to "predicates" with meaningful results (i.e.,
other than t/nil) like memq/assq.  I never considered either of these quys
one of the more elegant featues of lisp; it is clearly a kludge for not
having multiple return values.  Since most predicates are designed to
yield the exciting results t or nil, i dont think making a special internal
lambda variable to holddthat answer has much generality.