In Scheme, it's possible to have a stream with cycles. That is, a stream may contain itself as part of the stream definition.

scm> (define s (cons-stream 1 (cons-stream 2 s))) scm> (car s) 1 scm> (car (cdr-stream (cdr-stream s))) 1

Implement has-cycle, that returns whether a stream contains a cycle.

Note: You may assume that the input is either a stream of some unknown finite length, or contains a cycle.

(define (has-cycle s) 'YOUR-CODE-HERE )