[net.lang] FP puzzle

dfz (01/10/83)

Here is a Functional Programming puzzle for you.

Obtain a copy of the Springer-Verlag "Lecture Notes in Computer Science"
#107, "Formalization of Programming Concepts".
The first article in this journal is a reiteration by Backus of his
definition of FP.  Read the description of FP as presented on pages
three through five.  Now,

	1) show that the primitive function "null" is superfluous,
	   that is, it can be constructed of other FP primitives;

	2) show that the primitive function "distl" is superfluous;

	3) show that the primitive function "distr" is superfluous;

Send replies to D. F. Ziffer, ..!decvax!harpo!iwlc7!dfz
Good luck!