 variable and used in the subsequent expressions.
AND-LET* is a cross-breed between LET* and AND.

<H1>Rationale</H1>

<P>In case of an ordinary AND formed of proper boolean expressions:<BR>
(AND E1 E2 ...)<BR>
expression E2, if it gets to be evaluated, knows that E1 has returned
non-#f. Moreover, E2 knows exactly what the result of E1 was -- #t --
which E2 can use to its advantage. If E1 however is an extended
boolean expression, E2 can no longer tell which particular non-#f
value E1 has returned. Chances 