> (map car m)
(1 4 7 10)
> (map cadr m)
(2 5 8 11)
> (map caddr m)
(3 6 9 12)
> (get-row 2 m)
(7 8 9)
> (get-column 2 m)
(3 6 9 12)
> (transpose m)
((1 4 7 10) (2 5 8 11) (3 6 9 12))
> (transpose m)
[image] [image] mcar: contract violation
  expected: mpair?
  given: ()
> (transpose m)
((1 4 7 10) (2 5 8 11) (3 6 9 12))
> (map + '(1 2 3) (4 5 6))
[image] [image] application: not a procedure;
 expected a procedure that can be applied to arguments
  given: 4
> (mult-matrices m (transpose m))
((14 32 50 68) (32 77 122 167) (50 122 194 266) (68 167 266 365))
> (map + '(1 2 3) '(4 5 6) '(7 8 9))
(12 15 18)
> (map list '(1 2 3) '(4 5 6) '(7 8 9))
((1 4 7) (2 5 8) (3 6 9))
> (apply map (cons list '((1 2 3) (4 5 6) (7 8 9))))
((1 4 7) (2 5 8) (3 6 9))
> (apply map list '((1 2 3) (4 5 6) (7 8 9)))
((1 4 7) (2 5 8) (3 6 9))
> (apply + '(1 2 3 4 5))
15
> (apply + 6 '(1 2 3 4 5))
21
> (apply + 6 7 '(1 2 3 4 5))
28