count-if-not

(count-if-not predicate sequence &key key start end from-end)

Returns the number of elements of sequence that do not satisfy predicate -- the complement of count-if. The sequence may be a list, a vector or a string. :key selects what the predicate sees, :start/:end bound the scanned region, and :from-end is accepted but changes nothing (it only reorders the predicate calls, which cannot change a count).