one-item-in-deque.scm (317B)
1 (define-library (sicp solutions 3_23 one-item-in-deque) 2 (import (scheme base)) 3 4 (import (sicp solutions 3_23 front-ptr)) 5 6 (export one-item-in-deque?) 7 8 (begin 9 (define (one-item-in-deque? deque) 10 "Returns #t if there is one item in QUEUE, else returns #f. Raises an error if QUEUE is empty." 11 )))