From a1b1d10ad5fc505f8b83ac6976e5eb68b87427ff Mon Sep 17 00:00:00 2001
From: Masaya Tojo <masaya@tojo.tokyo>
Date: Wed, 12 Jun 2024 02:43:00 +0900
Subject: Add group modules

---
 algebraic-structures.group.make.scm | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 algebraic-structures.group.make.scm

(limited to 'algebraic-structures.group.make.scm')

diff --git a/algebraic-structures.group.make.scm b/algebraic-structures.group.make.scm
new file mode 100644
index 0000000..7568ac9
--- /dev/null
+++ b/algebraic-structures.group.make.scm
@@ -0,0 +1,16 @@
+(functor ((algebraic-structures group make) (M (<> unit inv)))
+    (<> unit inv pow)
+  (import M
+          scheme
+          (chicken base))
+
+  (define (pow x n)
+    (assert (exact-integer? n))
+    (if (negative? n)
+        (pow (inv x) (- n))
+        (let loop ((i n)
+                   (acc unit))
+          (if (= i 0)
+              acc
+              (loop (sub1 i)
+                    (<> acc x)))))))
-- 
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