Use Math.max to simplify

underscore.js

@@ -98,7 +98,7 @@
   var restParam = function(func, startIndex) {
     startIndex = startIndex == null ? func.length - 1 : +startIndex;
     return function() {
-      var length = arguments.length > startIndex ? arguments.length - startIndex : 0;
+      var length = Math.max(arguments.length - startIndex, 0);
       var rest = Array(length);
       for (var index = 0; index < length; index++) {
         rest[index] = arguments[index + startIndex];