More month comparison functions.

README.md

@@ -91,16 +91,19 @@ Functional Modules
 
 ### Member Base
 
+Specific Support Modules
+------------------------
+
 ### Month
 
 ### Period
 
 ### Primes
 
-Support Modules
+Generic Support Modules
----------------
+-----------------------
 
-There modules are not specific to this project but had to be
+These modules are not specific to this project but had to be
 implemented anyway to not require any external dependencies.
 
 ### ANSI

month.scm

@@ -34,6 +34,9 @@
   month->string
   month=?
   month<?
+  month<=?
+  month>=?
+  month>?
   month-diff
   month-add
   month-tests!
@@ -108,6 +111,19 @@
 	    (and (= (car m) (car n))
 		 (< (cadr m) (cadr n))))))
 
+ ;; Returns true if m is less than or equal n
+ (define (month<=? m n)
+   (or (month<? m n)
+       (month=? m n)))
+
+ ;; Returns true if m is greater than or equal to n
+ (define (month>=? m n)
+   (not (month<? m n)))
+
+ ;; Returns true if m is greater than n
+ (define (month>? m n)
+   (not (month<=? m n)))
+
  ;; Returns the number of months between from f and to t. The first
  ;; month is included in the count, the last month is not.
  (define (month-diff f t)