diff --git a/extensions/TeX/extpfeil.js b/extensions/TeX/extpfeil.js
new file mode 100644
index 000000000..19419c4f2
--- /dev/null
+++ b/extensions/TeX/extpfeil.js
@@ -0,0 +1,16 @@
+/*
+ *  /MathJax/extensions/TeX/extpfeil.js
+ *  
+ *  Copyright (c) 2010 Design Science, Inc.
+ *
+ *  Part of the MathJax library.
+ *  See http://www.mathjax.org for details.
+ * 
+ *  Licensed under the Apache License, Version 2.0;
+ *  you may not use this file except in compliance with the License.
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+MathJax.Hub.Register.StartupHook("TeX Jax Ready",function(){var b="1.1";var c=MathJax.InputJax.TeX,a=c.Definitions;MathJax.Hub.Insert(a,{macros:{xtwoheadrightarrow:["Extension","AMSmath"],xtwoheadleftarrow:["Extension","AMSmath"],xmapsto:["Extension","AMSmath"],xlongequal:["Extension","AMSmath"],xtofrom:["Extension","AMSmath"],Newextarrow:["Extension","AMSmath"]}});MathJax.Hub.Register.StartupHook("TeX AMSmath Ready",function(){MathJax.Hub.Insert(a,{macros:{xtwoheadrightarrow:["xArrow",8608,12,16],xtwoheadleftarrow:["xArrow",8606,17,13],xmapsto:["xArrow",8614,6,7],xlongequal:["xArrow",61,7,7],xtofrom:["xArrow",8644,12,12],Newextarrow:"NewExtArrow"}})});c.Parse.Augment({NewExtArrow:function(d){var f=this.GetArgument(d),g=this.GetArgument(d),e=this.GetArgument(d);if(!f.match(/^\\([a-z]+|.)$/i)){c.Error("First argument to "+d+" must be a control sequence name")}if(!g.match(/^(\d+),(\d+)$/)){c.Error("Second argument to "+d+" must be two integers separated by a comma")}if(!e.match(/^(\d+|0x[0-9A-F]+)$/i)){c.Error("Third argument to "+d+" must be a unicode character number")}f=f.substr(1);g=g.split(",");e=parseInt(e);a.macros[f]=["xArrow",e,parseInt(g[0]),parseInt(g[1])]}});MathJax.Hub.Startup.signal.Post("TeX extpfeil Ready")});MathJax.Ajax.loadComplete("[MathJax]/extensions/TeX/extpfeil.js");
+
diff --git a/unpacked/extensions/TeX/extpfeil.js b/unpacked/extensions/TeX/extpfeil.js
new file mode 100644
index 000000000..43c8306a0
--- /dev/null
+++ b/unpacked/extensions/TeX/extpfeil.js
@@ -0,0 +1,84 @@
+/*************************************************************
+ *
+ *  MathJax/extensions/TeX/extpfeil.js
+ *  
+ *  Implements additional stretchy arrow macros.
+ *
+ *  ---------------------------------------------------------------------
+ *  
+ *  Copyright (c) 2011 Design Science, Inc.
+ * 
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+MathJax.Hub.Register.StartupHook("TeX Jax Ready",function () {
+  var VERSION = "1.1";
+  
+  var TEX = MathJax.InputJax.TeX,
+      TEXDEF = TEX.Definitions;
+  
+  //
+  //  Define the arrows to load the AMSmath extension
+  //  (since they need its xArrow method)
+  // 
+  MathJax.Hub.Insert(TEXDEF,{
+    macros: {
+      xtwoheadrightarrow: ['Extension','AMSmath'],
+      xtwoheadleftarrow:  ['Extension','AMSmath'],
+      xmapsto:            ['Extension','AMSmath'],
+      xlongequal:         ['Extension','AMSmath'],
+      xtofrom:            ['Extension','AMSmath'],
+      Newextarrow:        ['Extension','AMSmath']
+    }
+  });
+  
+  //
+  //  Redefine the macros when AMSmath is loaded
+  //
+  MathJax.Hub.Register.StartupHook("TeX AMSmath Ready",function () {
+    MathJax.Hub.Insert(TEXDEF,{
+      macros: {
+        xtwoheadrightarrow: ['xArrow',0x21A0,12,16],
+        xtwoheadleftarrow:  ['xArrow',0x219E,17,13],
+        xmapsto:            ['xArrow',0x21A6,6,7],
+        xlongequal:         ['xArrow',0x003D,7,7],
+        xtofrom:            ['xArrow',0x21C4,12,12],
+        Newextarrow:        'NewExtArrow'
+      }
+    });
+  });
+
+  //
+  //  Implements \Newextarrow to define a new arrow (not compatible with \newextarrow, but
+  //  the equivalent for MathJax)
+  //
+  TEX.Parse.Augment({
+    NewExtArrow: function (name) {
+      var cs     = this.GetArgument(name),
+          space = this.GetArgument(name),
+          chr   = this.GetArgument(name);
+      if (!cs.match(/^\\([a-z]+|.)$/i))
+        {TEX.Error("First argument to "+name+" must be a control sequence name")}
+      if (!space.match(/^(\d+),(\d+)$/))
+        {TEX.Error("Second argument to "+name+" must be two integers separated by a comma")}
+      if (!chr.match(/^(\d+|0x[0-9A-F]+)$/i))
+        {TEX.Error("Third argument to "+name+" must be a unicode character number")}
+      cs = cs.substr(1); space = space.split(","); chr = parseInt(chr);
+      TEXDEF.macros[cs] = ['xArrow',chr,parseInt(space[0]),parseInt(space[1])];
+    }
+  });
+  
+  MathJax.Hub.Startup.signal.Post("TeX extpfeil Ready");
+});
+
+MathJax.Ajax.loadComplete("[MathJax]/extensions/TeX/extpfeil.js");