member of one list is a member of the other
Major Section: ACL2-BUILT-INS
General Forms: (subsetp x y) (subsetp x y :test 'eql) ; same as above (eql as equality test) (subsetp x y :test 'eq) ; same, but eq is equality test (subsetp x y :test 'equal) ; same, but equal is equality test
(Subsetp x y) is true if and only if every member of the list x
is a member of the list y. The optional keyword, :TEST,
has no effect logically, but provides the test (default eql) used for
comparing members of the two lists.
The guard for a call of subsetp depends on the test. In all cases,
both arguments must satisfy true-listp. If the test is eql, then
one of the arguments must satisfy eqlable-listp. If the test is
eq, then one of the arguments must satisfy symbol-listp.
See equality-variants for a discussion of the relation between subsetp and
its variants:
(subsetp-eq x lst)is equivalent to(subsetp x lst :test 'eq);
(subsetp-equal x lst)is equivalent to(subsetp x lst :test 'equal).
In particular, reasoning about any of these primitives reduces to reasoning
about the function subsetp-equal.
Subsetp is defined by Common Lisp. See any Common Lisp documentation for
more information.