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-rw-r--r--net/ricketyspace/sicp/two/twentynine.scm11
1 files changed, 6 insertions, 5 deletions
diff --git a/net/ricketyspace/sicp/two/twentynine.scm b/net/ricketyspace/sicp/two/twentynine.scm
index cc1380c..8e1aaa2 100644
--- a/net/ricketyspace/sicp/two/twentynine.scm
+++ b/net/ricketyspace/sicp/two/twentynine.scm
@@ -27,12 +27,13 @@
(define (branch-structure branch)
(car (cdr branch)))
+(define (branch-weight b)
+ (let ((bs (branch-structure b)))
+ (cond ((not (pair? bs)) bs)
+ (else (+ (branch-weight (left-branch bs))
+ (branch-weight (right-branch bs)))))))
+
(define (total-weight mobile)
- (define (branch-weight b)
- (let ((bs (branch-structure b)))
- (cond ((not (pair? bs)) bs)
- (else (+ (branch-weight (left-branch bs))
- (branch-weight (right-branch bs)))))))
(+ (branch-weight (left-branch mobile))
(branch-weight (right-branch mobile))))