eql
as test
Major Section: PROGRAMMING
(Member x l)
equals the longest tail of l
that begins with
x
, or else nil
if no such tail exists.
(Member x l)
is provably the same in the ACL2 logic as
(member-equal x l)
. It has a stronger guard than member-equal
because uses eql
to test for whether x
is equal to a given
member of l
. Its guard requires that l
is a true list, and
moreover, either (eqlablep x)
or all members of l
are
eqlablep
. See member-equal and see member-eq.
Member
is a Common Lisp function. See any Common Lisp
documentation for more information. Since ACL2 functions cannot
take keyword arguments (though macros can), the ACL2 functions
member-equal
and member-eq
are defined to correspond to calls
of the Common Lisp function member
whose keyword argument
:test
is equal
or eq
, respectively.