(define make-scaled
(lambda (scale f)
(lambda (x) (* scale (f x)))))
(define add-one
(lambda (x) (+ 1 x)))
(define mystery
(make-scaled 3 add-one))
| Q: What is | (mystery 4)? |
| ↓ | |
| ((make-scaled 3 add-one) 4) | |
| ↓ | |
| ((lambda (x) (* 3 (add-one x))) 4) | |
| ↓ | |
| (* 3 (add-one 4)) | |
| ↓ | |
| (* 3 5) |