Fine with me, though note that the definition for ARRAY-INDEX given in CDR 5 is bogus -- ARRAY-TOTAL-SIZE is wrong.
(And I kind of prefer our old definition otherwise as well.)
i've pushed an almost complete cdr5 implementation. i've tried to check it properly but it's lacking a complete unit-test, so take it with a piece of salt.
array-index is left untouched, i just moved it into types.lisp from arrays.lisp