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| -rw-r--r-- | net/ricketyspace/sicp/two/seven.scm | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/net/ricketyspace/sicp/two/seven.scm b/net/ricketyspace/sicp/two/seven.scm new file mode 100644 index 0000000..6b0375b --- /dev/null +++ b/net/ricketyspace/sicp/two/seven.scm @@ -0,0 +1,18 @@ +;;;; Under Creative Commons Attribution-ShareAlike 4.0 +;;;; International. See +;;;; <https://creativecommons.org/licenses/by-sa/4.0/>. + +(define-module (net ricketyspace sicp two seven) + #:export (make-interval + lower-bound + upper-bound + add-interval)) + +(define (make-interval a b) (cons a b)) + +(define (lower-bound x) (car x)) +(define (upper-bound x) (cdr x)) + +(define (add-interval x y) + (make-interval (+ (lower-bound x) (lower-bound y)) + (+ (upper-bound x) (upper-bound y)))) |