Code Review
Compare your solutions
(define (lookup given-key tree-of-records)
(if (null? tree-of-records)
#f
(let ((entry-key (key (entry tree-of-records))))
(cond ((= given-key entry-key)
(entry tree-of-records))
((> given-key entry-key)
(lookup given-key (right-branch tree-of-records)))
((< given-key entry-key)
(lookup given-key (left-branch tree-of-records)))))))
(define (lookup given-key tree-of-records)
(if (null? tree-of-records)
#f
(let ((entry-key (key (entry tree-of-records))))
(cond ((= given-key entry-key)
(entry tree-of-records))
((> given-key entry-key)
(lookup given-key (right-branch tree-of-records)))
((< given-key entry-key)
(lookup given-key (left-branch tree-of-records)))))))