are it took a lot of work to evaluate
E1, and the produced result (a number, a vector, a string, etc) may be
of value to E2. Alas, the AND form merely checks that the result is
not an #f, and throws it away. If E2 needs it, it has to compute that
value anew. This proposed AND-LET* special form lets constituent
expressions get hold of the results of already evaluated expressions,
without re-doing their work.

<P>AND-LET* can be thought of as a combination of LET* and AND, or a
generalization of COND's send o