From 020c1e77489b772f854bb3288b9c8d2818a6bf9d Mon Sep 17 00:00:00 2001
From: EuAndreh <eu@euandre.org>
Date: Fri, 18 Apr 2025 02:17:12 -0300
Subject: git mv src/content/* src/content/en/

---
 src/content/en/pastebins/2021/09/02/sicp-3-19.adoc | 33 ++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 src/content/en/pastebins/2021/09/02/sicp-3-19.adoc

(limited to 'src/content/en/pastebins/2021/09/02/sicp-3-19.adoc')

diff --git a/src/content/en/pastebins/2021/09/02/sicp-3-19.adoc b/src/content/en/pastebins/2021/09/02/sicp-3-19.adoc
new file mode 100644
index 0000000..166170f
--- /dev/null
+++ b/src/content/en/pastebins/2021/09/02/sicp-3-19.adoc
@@ -0,0 +1,33 @@
+= SICP exercise 3.19
+:categories: lisp programming-languages
+
+[source,scheme]
+----
+(define (cycle? l)
+  (define (rec l x)
+    (cond
+      ((null? x) false)
+      ((eq? l x) true)
+      (true (rec l (cdr x)))))
+  (rec l (cdr l)))
+----
+
+Sample interactive session:
+
+[source,scheme]
+----
+scheme@(guile-user)> (define true #t)
+scheme@(guile-user)> (define false #f)
+scheme@(guile-user)>
+(define (cycle? l)
+  (define (rec l x)
+    (cond
+      ((null? x) false)
+      ((eq? l x) true)
+      (true (rec l (cdr x)))))
+  (rec l (cdr l)))
+scheme@(guile-user)> (cycle? '(1 2 3))
+$9 = #f
+scheme@(guile-user)> (cycle? (make-cycle '(1 2 3)))
+$10 = #t
+----
-- 
cgit v1.2.3

