(member 'a '(a b))
(A B)
> (member '(a) '((a) (b)))
NIL
> (eq 'a 'a)
T
> (eq '(a b) '(a b))
NIL
> (equal 'a 'a)
T
> (equal '(a b) '(a b))
T
> (defun memset (Sex Set) (cond
( (null Set) nil)
( (equal Sex (car Set)) Set)
( t (memset Sex (cdr Set))) ))
MEMSET
> (memset 'a '(a b))
(A B)
> (memset '(a) '((a) (b)))
((A) (B))
> (defun union (S1 S2) (cond
( (null S1) S2)
( (memset (car S1) S2) (union (cdr S1) S2) )
( 'else (cons (car S1) (union (cdr S1) S2))) ))
UNION
> (union nil '(a b))
(A B)
> (union '(a b) ())
(A B)
> (union '(a b) '( c d))
(A B C D)
> (union '(a b) '(b c d))
(A B C D)
> (union '(b a) '(b c d))
(A B C D)
> (defun inter (S1 S2) (cond
( (null S1) nil)
( (memset (car S1) S2) (cons (car S1) (inter (cdr S1) S2)))
( t (inter (cdr S1) S2)) ))
INTER
> (inter '(a b) '(c d))
NIL
> (inter nil '(a b))
NIL
> (inter '(a b) '())
NIL
> (inter '(a b) '(b c d))
(B)
> (inter '(b a) '(b c d))
(B)
> (defun makeset (lis) (cond
                         ((null lis)                nil)
                         ((memset (car lis) (cdr lis))   (makeset (cdr lis)))
                         ('esle     (cons (first lis) (makeset (rest lis))))
))
MAKESET
> (makeset nil)
NIL
> (makeset '(a b))
(A B)
> (makeset '(a a b b c d))
(A B C D)
> (makeset '(e a b b c d))
(E A B C D)
> (mapcar 'odd '(1 2 3))
Error: The function ODD is not defined.
Happened in: #<Subr-MAPCAR: #9f3ad8>
> (oddp 1)
T
> (defun odd (n) (oddp n))
ODD
> (mapcar 'odd '(1 2 3))
(T NIL T)
> (defun mymapcar (f lis)(cond
                           ((null lis)    nil)
                           ('else (cons
                                  (funcall f (car lis))
                                  (mymapcar f (rest lis))))
))
MYMAPCAR
> (mymapcar 'odd '(1 2 3))
(T NIL T)
> (mymapcar #'odd '(1 2 3))
(T NIL T)
> (exit)