browser versions

dist/index.js

@@ -26,10 +26,6 @@ var _import = require('./helpers');
 
 var _ = _interopRequireWildcard(_import);
 
-var _polyfills = require('babel/polyfill');
-
-var _polyfills2 = _interopRequireWildcard(_polyfills);
-
 var Equation = {
   /**
     * Solves the given math expression, following these steps:
@@ -189,7 +185,7 @@ var parseGroups = function parseGroups(stack) {
   // Parantheses become inner arrays which will then be processed first
   var sub = 0;
   return stack.reduce(function (a, b) {
-    if (b.includes('(')) {
+    if (b.indexOf('(') > -1) {
       if (b.length > 1) {
         _.dive(a, sub).push(b.replace('(', ''), []);
       } else {