From c3f051ee8bcec87d904428731f2659cd0bbf9612 Mon Sep 17 00:00:00 2001
From: Devan Patel <devanp92@ufl.edu>
Date: Mon, 4 May 2015 16:03:59 -0400
Subject: [PATCH] Fixing IntegerOverflow on Composition. Updated tests as well.

---
 lib/function/combinatorics/composition.js  | 2 +-
 test/function/combinatorics/composition.js | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/function/combinatorics/composition.js b/lib/function/combinatorics/composition.js
index 6f074ee8e..9b34f3a30 100644
--- a/lib/function/combinatorics/composition.js
+++ b/lib/function/combinatorics/composition.js
@@ -57,7 +57,7 @@ module.exports = function (math) {
       if (k.gt(n)) {
         throw new TypeError('k must be less than n in function composition');
       }
-      return math.combinations(n-1,k-1);
+      return math.combinations(n.minus(1), k.minus(1));
     } else {
       throw new TypeError('Integer values are expected in composition')
     }
diff --git a/test/function/combinatorics/composition.js b/test/function/combinatorics/composition.js
index e6e2b7d28..399fa80cb 100644
--- a/test/function/combinatorics/composition.js
+++ b/test/function/combinatorics/composition.js
@@ -14,6 +14,7 @@ describe('composition', function() {
   it('should calculate the composition of n items taken k at a time with BigNumbers', function(){
     assert.equal(composition(math.bignumber(7), math.bignumber(5)), math.bignumber(15));
     assert.equal(composition(math.bignumber(70), math.bignumber(3)), math.bignumber(2346));
+    assert.equal(composition(math.bignumber(56), math.bignumber(11)), math.bignumber(29248649430));
   });
 
   it('should not work with non-integer and negative input', function() {