: member? ( elt seq -- ? )
[ = ] with any? ;
-: member-of? ( seq elt -- ? )
- [ = ] curry any? ;
-
: member-eq? ( elt seq -- ? )
[ eq? ] with any? ;
-: member-eq-of? ( seq elt -- ? )
- [ eq? ] curry any? ;
-
: remove ( elt seq -- newseq )
[ = ] with reject ;
-: remove-of ( seq elt -- newseq )
- [ = ] curry reject ;
-
: remove-eq ( elt seq -- newseq )
[ eq? ] with reject ;
-: remove-eq-of ( seq elt -- newseq )
- [ eq? ] curry reject ;
-
: sift ( seq -- newseq )
[ ] filter ;