every, some, notevery, and notany
test elements of sequences for satisfaction of a given predicate.
The first argument to predicate is an element of the first sequence;
each succeeding argument is an element of a succeeding sequence.
Predicate is first applied to the elements
with index 0 in each of the sequences, and possibly then to
the elements with index 1, and so on, until a termination
criterion is met or the end of the shortest of the sequences is reached.
every returns false as soon
as any invocation of predicate returns false.
If the end of a sequence is reached,
every returns true.
Thus, every returns true if and only if
every invocation of predicate returns true.
some returns the first non-nil value
which is returned by an invocation of predicate.
If the end of a sequence is reached without any invocation of the
predicate returning true, some returns false.
Thus, some returns true if and only if
some invocation of predicate returns true.
notany returns false
as soon as any invocation of predicate returns true.
If the end of a sequence is reached,
notany returns true.
Thus, notany returns true if and only if
it is not the case that any invocation of predicate returns true.
notevery returns true as soon as any invocation of
predicate returns false.
If the end of a sequence is reached,
notevery returns false.
Thus, notevery returns true if and only if
it is not the case that every invocation of predicate returns true.