#!+sb-doc
"Takes an object and a location holding a list. If the object is
already in the list, does nothing; otherwise, conses the object onto
the list. Returns the modified list. If there is a :TEST keyword, this
is used for the comparison."
#!+sb-doc
"Takes an object and a location holding a list. If the object is
already in the list, does nothing; otherwise, conses the object onto
the list. Returns the modified list. If there is a :TEST keyword, this
is used for the comparison."