diff --git a/src/www/syntax-editor/README.md b/src/www/syntax-editor/README.md
index 647792d48..dec633476 100644
--- a/src/www/syntax-editor/README.md
+++ b/src/www/syntax-editor/README.md
@@ -9,7 +9,7 @@ An improved version of the [old syntax editor][1].
 
 ## Notes
 
-Tested with latest Chrome and Firefox.
+- Tested with latest Chrome and Firefox (only).
 
 ## TODO
 
@@ -19,7 +19,6 @@ Tested with latest Chrome and Firefox.
 - UI issue with DisambPhrasebookEng
 - more prominence to Disamb-linearizations
 - ambiguity: (optionally) parse all the resulting linearizations/variants and point out those which are ambiguous
-- random-generate a non-empty tree as a starting point
 - try to retain subtree when replacing node
 - add undo/redo (or back/forward) navigation
 - structure the set of fridge magnets some more. Even though they
diff --git a/src/www/syntax-editor/js/ast.js b/src/www/syntax-editor/ast.js
similarity index 79%
rename from src/www/syntax-editor/js/ast.js
rename to src/www/syntax-editor/ast.js
index 633bdc2b6..143b9836c 100644
--- a/src/www/syntax-editor/js/ast.js
+++ b/src/www/syntax-editor/ast.js
@@ -35,10 +35,9 @@ function NodeID(x) {
 function ASTNode(data) {
     for(var d in data) this[d]=data[d];
     this.children = [];
-    // if (children != undefined)
-    //     for (c in children) {
-    //         this.children.push( new ASTNode(children[c]) );
-    //     }
+    for (c in data.children) {
+        this.children.push( new ASTNode(data.children[c]) );
+    }
     this.hasChildren = function(){
         return this.children.length > 0;
     }
@@ -84,7 +83,6 @@ function AST(fun, cat) {
         this.find(this.current).cat = c;
     }
 
-
     // Add a single fun at current node
     this.add = function(fun, cat) {
         this._add(this.current, newNode(fun,cat));
@@ -101,33 +99,39 @@ function AST(fun, cat) {
         this._setSubtree(this.current, node);
     }
     
-    // set tree at given id to 
-    this._setSubtree = function(id, node) {
-        var x = this.find(id);
-        for (var n in node) x[n] = node[n];
+    // set tree at given id
+    this._setSubtree = function(id, subtree) {
+        var lid = id.get().slice(); // clone NodeID array
+        var node = this.root;
+
+        if (lid.length==1)
+            // Insert at root
+            this.root = new ASTNode(subtree);
+        else {
+            lid.shift(); // throw away root
+            while (lid.length>1 && node.hasChildren()) {
+                node = node.children[lid.shift()];
+            }
+            node.children[lid.shift()] = new ASTNode(subtree);
+        }
 
-        x.traverse(function(node){
-            if (!node.children) node.children=[];
-            // TODO: this doesn't work!
-            //node = new ASTNode(node);
-        })
     }
 
     // id should be a list of child indices [0,1,0]
     // or a string separated by commas "0,1,0"
-    this.find = function(_id) {
-        var id = undefined
-        switch (typeof _id) {
-        case "number": id = [_id]; break;
-        case "string": id = _id.split(","); break;
-        case "object": id = _id.get().slice(); break; // clone NodeID array
+    this.find = function(id) {
+        var lid = undefined
+        switch (typeof id) {
+        case "number": lid = [id]; break;
+        case "string": lid = id.split(","); break;
+        case "object": lid = id.get().slice(); break; // clone NodeID array
         }
         var node = this.root;
-        if (id[0] == 0) id.shift();
-        while (id.length>0 && node.children.length>0) {
-            node = node.children[id.shift()];
+        if (lid[0] == 0) lid.shift();
+        while (lid.length>0 && node.children.length>0) {
+            node = node.children[lid.shift()];
         }
-        if (id.length>0)
+        if (lid.length>0)
             return undefined;
         return node;
     }
@@ -187,8 +191,8 @@ function AST(fun, cat) {
         var s = "";
         function visit(node) {
             s += node.fun ? node.fun : "?" ;
-//            if (!node.hasChildren())
-            if (node.children.length == 0)
+            if (!node.hasChildren())
+//            if (node.children.length == 0)
                 return;
             for (i in node.children) {
                 s += " (";
diff --git a/src/www/syntax-editor/ui/style.css b/src/www/syntax-editor/editor.css
similarity index 95%
rename from src/www/syntax-editor/ui/style.css
rename to src/www/syntax-editor/editor.css
index 127b1ad2a..8640a819f 100644
--- a/src/www/syntax-editor/ui/style.css
+++ b/src/www/syntax-editor/editor.css
@@ -43,7 +43,7 @@ select#to_menu
 
 #linearisations
 {
-  background: rgba(170, 170, 170, 0.5);
+  /* background: rgba(170, 170, 170, 0.5); */
   padding:0.5em;
   margin:0.5em 0;
   }
diff --git a/src/www/syntax-editor/editor.html b/src/www/syntax-editor/editor.html
index d641998ab..bb6b49fa8 100644
--- a/src/www/syntax-editor/editor.html
+++ b/src/www/syntax-editor/editor.html
@@ -5,7 +5,7 @@
   <link rel="author" href="http://www.grammaticalframework.org/~john/" title="John J. Camilleri">
   <title>Syntax Editor</title>
   <link rel="stylesheet" type="text/css" href="http://cloud.grammaticalframework.org/minibar/minibar.css" />
-  <link rel="stylesheet" type="text/css" href="ui/style.css" />
+  <link rel="stylesheet" type="text/css" href="editor.css" />
 </head>
 <body>
   <h2>Syntax Editor</h2>
@@ -17,16 +17,15 @@
   John J. Camilleri, November 2012
   </small>
 
-  <script type="text/javascript" src="js/support.js"></script>
-  <script type="text/javascript" src="js/pgf_online.js"></script>
-  <script type="text/javascript" src="js/ast.js"></script>
-  <script type="text/javascript" src="js/editor_menu.js"></script>
-  <script type="text/javascript" src="js/editor.js"></script>
+  <script type="text/javascript" src="../js/support.js"></script>
+  <script type="text/javascript" src="../js/pgf_online.js"></script>
+  <script type="text/javascript" src="ast.js"></script>
+  <script type="text/javascript" src="editor_menu.js"></script>
+  <script type="text/javascript" src="editor.js"></script>
   <script type="text/javascript">
-    // Code taken from minibar_online.js
     var server_options = {
-        //grammars_url: "http://www.grammaticalframework.org/grammars/",
-        //grammars_url: "http://localhost:41296/grammars/",
+        // grammars_url: "http://www.grammaticalframework.org/grammars/",
+        grammars_url: "http://localhost:41296/grammars/",
     }
     var editor_options = {
 	target: "editor"
diff --git a/src/www/syntax-editor/js/editor.js b/src/www/syntax-editor/editor.js
similarity index 97%
rename from src/www/syntax-editor/js/editor.js
rename to src/www/syntax-editor/editor.js
index 1f6a374b5..33b8b496c 100644
--- a/src/www/syntax-editor/js/editor.js
+++ b/src/www/syntax-editor/editor.js
@@ -243,7 +243,6 @@ Editor.prototype.delete_refinement = function() {
 // Generate random subtree from current node
 Editor.prototype.generate_random = function() {
     var t = this;
-    t.ui.refinements.innerHTML = "...";
     t.ast.removeChildren();
     var args = {
         cat: t.ast.getCat(),
@@ -263,7 +262,7 @@ Editor.prototype.generate_random = function() {
     server.get_random(args, cont, err);
 }
 
-// Import AST from string representation
+// Import AST from string representation, setting at current node
 Editor.prototype.import_ast = function(abstr) {
     var t = this;
     var args = {
@@ -272,7 +271,9 @@ Editor.prototype.import_ast = function(abstr) {
     var cont = function(tree){
         // Build tree of just fun, then populate with cats
         t.ast.setSubtree(tree);
+        /// TODO: traverse only subtree, not everything!
         t.ast.traverse(function(node){
+            if (!node.fun) return;
             var info = t.lookup_fun(node.fun);
             node.cat = info.cat;
         });
@@ -282,7 +283,8 @@ Editor.prototype.import_ast = function(abstr) {
     server.pgf_call("abstrjson", args, cont);
 }
 
-// Look up information for a function, hopefully from cache
+// Look up information for a function
+// This will absolutely fail on dependant types
 Editor.prototype.lookup_fun = function(fun) {
     var t = this;
     var def = t.grammar_constructors.funs[fun].def;
diff --git a/src/www/syntax-editor/js/editor_menu.js b/src/www/syntax-editor/editor_menu.js
similarity index 100%
rename from src/www/syntax-editor/js/editor_menu.js
rename to src/www/syntax-editor/editor_menu.js
diff --git a/src/www/syntax-editor/js/pgf_online.js b/src/www/syntax-editor/js/pgf_online.js
deleted file mode 100644
index 6fe23b13e..000000000
--- a/src/www/syntax-editor/js/pgf_online.js
+++ /dev/null
@@ -1,80 +0,0 @@
-
-/* --- Grammar access object ------------------------------------------------ */
-
-function pgf_online(options) {
-    var server = {
-	// State variables (private):
-	grammars_url: "/grammars/",
-	other_grammars_urls: [],
-	grammar_list: null,
-	current_grammar_url: null,
-
-	// Methods:
-	switch_grammar: function(grammar_url,cont) {
- 	    this.current_grammar_url=this.grammars_url+grammar_url;
-	    if(cont) cont();
-	},
-	add_grammars_url: function(grammars_url,cont) {
-	    this.other_grammars_urls.push(grammars_url);
-	    if(cont) cont();
-	},
-	switch_to_other_grammar: function(grammar_url,cont) {
- 	    this.current_grammar_url=grammar_url;
-	    if(cont) cont();
-	},
-	get_grammarlist: function(cont,err) {
-	    if(this.grammar_list) cont(this.grammar_list)
-	    else http_get_json(this.grammars_url+"grammars.cgi",cont,err);
-	},
-	get_grammarlists: function(cont,err) { // May call cont several times!
-	    var ds=this.other_grammars_urls;
-	    var n=1+ds.length;
-	    function pair(dir) {
-		return function(grammar_list){cont(dir,grammar_list,n)}
-	    }
-	    function ignore_error(err) { console.log(err) }
-	    this.get_grammarlist(pair(this.grammars_url),err)
-	    for(var i in ds)
-		http_get_json(ds[i]+"grammars.cgi",pair(ds[i]),ignore_error);
-	},
-	pgf_call: function(cmd,args,cont,err) {
-	    var url=this.current_grammar_url+"?command="+cmd+encodeArgs(args)
-	    http_get_json(url,cont,err);
-	},
-	
-	get_languages: function(cont,err) {
-	    this.pgf_call("grammar",{},cont,err);
-	},
-	grammar_info: function(cont,err) {
-	    this.pgf_call("grammar",{},cont,err);
-	},
-	
-	get_random: function(args,cont,err) { // cat, limit
-	    args.random=Math.random(); // side effect!!
-	    this.pgf_call("random",args,cont,err);
-	},
-	linearize: function(args,cont,err) { // tree, to
-	    this.pgf_call("linearize",args,cont,err);
-	},
-	complete: function(args,cont,err) { // from, input, cat, limit
-	    this.pgf_call("complete",args,cont,err);
-	},
-	parse: function(args,cont,err) { // from, input, cat
-	    this.pgf_call("parse",args,cont,err);
-	},
-	translate: function(args,cont,err) { // from, input, cat, to
-	    this.pgf_call("translate",args,cont,err);
-	},
-	translategroup: function(args,cont,err) { // from, input, cat, to
-	    this.pgf_call("translategroup",args,cont,err);
-	},
-	browse: function(args,cont,err) { // id, format
-	    if(!args.format) args.format="json"; // sife effect!!
-	    this.pgf_call("browse",args,cont,err);
-	}
-    };
-    for(var o in options) server[o]=options[o];
-    if(server.grammar_list && server.grammar_list.length>0)
-	server.switch_grammar(server.grammar_list[0]);
-    return server;
-}
diff --git a/src/www/syntax-editor/js/support.js b/src/www/syntax-editor/js/support.js
deleted file mode 100644
index e82f4fc9c..000000000
--- a/src/www/syntax-editor/js/support.js
+++ /dev/null
@@ -1,329 +0,0 @@
-/* --- Accessing document elements ------------------------------------------ */
-
-function element(id) {
-  return document.getElementById(id);
-}
-
-/* --- JavaScript tricks ---------------------------------------------------- */
-
-// To be able to use object methods that refer to "this" as callbacks
-// See section 3.3 of https://github.com/spencertipping/js-in-ten-minutes/raw/master/js-in-ten-minutes.pdf
-function bind(f, this_value) {
-    return function () {return f.apply (this_value, arguments)};
-};
-
-// Implement Array.isArray for older browsers that lack it.
-// https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/isArray
-if(!Array.isArray) {
-    Array.isArray = function (arg) {
-        return Object.prototype.toString.call(arg) == '[object Array]';
-    };
-}
-
-/* --- JSONP ---------------------------------------------------------------- */
-
-// Inspired by the function jsonp from 
-//          http://www.west-wind.com/Weblog/posts/107136.aspx
-// See also http://niryariv.wordpress.com/2009/05/05/jsonp-quickly/
-//          http://en.wikipedia.org/wiki/JSONP
-function jsonp(url,callback)
-{                
-    if (url.indexOf("?") > -1)
-        url += "&jsonp=" 
-    else
-        url += "?jsonp=" 
-    url += callback;
-    //url += "&" + new Date().getTime().toString(); // prevent caching        
-    
-    var script = empty("script");        
-    script.setAttribute("src",url);
-    script.setAttribute("type","text/javascript");                
-    document.body.appendChild(script);
-}
-
-var json = {next:0};
-
-// Like jsonp, but instead of passing the name of the callback function, you 
-// pass the callback function directly, making it possible to use anonymous
-// functions.
-function jsonpf(url,callback,errorcallback)
-{
-    var name="callback"+(json.next++);
-    json[name]=function(x) { delete json[name]; callback(x); }
-    jsonp(url,"json."+name);
-}
-
-/* --- AJAX ----------------------------------------------------------------- */
-
-function GetXmlHttpObject(handler)
-{ 
-  var objXMLHttp=null
-  if (window.XMLHttpRequest)
-  {
-    // See http://www.w3.org/TR/XMLHttpRequest/
-    //     https://developer.mozilla.org/en/xmlhttprequest
-    objXMLHttp=new XMLHttpRequest()
-  }
-  else if (window.ActiveXObject)
-  {
-    objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP")
-  }
-  return objXMLHttp
-}
-
-function ajax_http(method,url,body,callback,errorcallback) {
-    var http=GetXmlHttpObject()
-    if (!http) {
-	var errortext="Browser does not support HTTP Request";
-	if(errorcallback) errorcallback(errortext,500)
-	else alert(errortext)
-    }
-    else {
-	function statechange() {
-	    if (http.readyState==4 || http.readyState=="complete") {
-		if(http.status<300) callback(http.responseText,http.status);
-		else if(errorcallback)
-		    errorcallback(http.responseText,http.status,
-				  http.getResponseHeader("Content-Type"));
-		else alert("Request for "+url+" failed: "
-			   +http.status+" "+http.statusText);
-	    }
-	}
-	http.onreadystatechange=statechange;
-	http.open(method,url,true)
-	http.send(body)
-    }
-    return http
-}
-
-function ajax_http_get(url,callback,errorcallback) {
-    ajax_http("GET",url,null,callback,errorcallback)
-}
-
-function ajax_http_post(url,formdata,callback,errorcallback) {
-    ajax_http("POST",url,formdata,callback,errorcallback)
-    // See https://developer.mozilla.org/En/XMLHttpRequest/Using_XMLHttpRequest#Using_FormData_objects
-}
-
-// JSON via AJAX
-function ajax_http_get_json(url,cont,errorcallback) {
-    ajax_http_get(url,function(txt){cont(eval("("+txt+")"));}, errorcallback);
-}
-
-function sameOrigin(url) {
-    var a=empty("a");
-    a.href=url; // converts to an absolute URL
-    return hasPrefix(a.href,location.protocol+"//"+location.host+"/");
-}
-
-// Use AJAX when possible, fallback to JSONP
-function http_get_json(url,cont,errorcallback) {
-    if(sameOrigin(url)) ajax_http_get_json(url,cont,errorcallback);
-    else jsonpf(url,cont,errorcallback);
-}
-
-/* --- URL construction ----------------------------------------------------- */
-
-function encodeArgs(args) {
-    var q=""
-    for(var arg in args)
-	if(args[arg]!=undefined)
-	    q+="&"+arg+"="+encodeURIComponent(args[arg]);
-    return q;
-}
-
-/* --- HTML construction ---------------------------------------------------- */
-function text(s) { return document.createTextNode(s); }
-
-function node(tag,as,ds) {
-    var n=document.createElement(tag);
-    for(var a in as) n.setAttribute(a,as[a]);
-    if(ds) for(var i in ds) n.appendChild(ds[i]);
-    return n;
-}
-
-function empty(tag,name,value) {
-    var el=node(tag,{},[])
-    if(name && value) el.setAttribute(name,value);
-    return el;
-}
-
-function empty_id(tag,id) { return empty(tag,"id",id); }
-function empty_class(tag,cls) { return empty(tag,"class",cls); }
-
-function div_id(id,cs) { return node("div",{id:id},cs); }
-function span_id(id) { return empty_id("span",id); }
-
-function wrap(tag,contents) {
-    return node(tag,{},Array.isArray(contents) ? contents : [contents]);
-}
-
-function wrap_class(tag,cls,contents) {
-    return node(tag,{"class":cls},
-		contents ? Array.isArray(contents) ? 
-		contents : [contents] : [])
-}
-
-function span_class(cls,contents) { return wrap_class("span",cls,contents); }
-function div_class(cls,contents)  { return wrap_class("div",cls,contents); }
-
-function p(contents) { return wrap("p",contents); }
-function dt(contents) { return wrap("dt",contents); }
-function dd(contents) { return wrap("dd",contents); }
-function li(contents) { return wrap("li",contents); }
-
-function th(contents) { return wrap("th",contents); }
-function td(contents) { return wrap("td",contents); }
-
-function tr(cells)    { return wrap("tr",cells); }
-
-function button(label,action,key) {
-    var el=node("input",{"type":"button","value":label},[]);
-    if(typeof action=="string") el.setAttribute("onclick",action);
-    else el.onclick=action;
-    if(key) el.setAttribute("accesskey",key);
-    return el;
-}
-
-function option(label,value) {
-    return node("option",{"value":value},[text(label)]);
-}
-
-function hidden(name,value) {
-    return node("input",{type:"hidden",name:name,value:value},[])
-}
-
-function tda(cs) { return node("td",{},cs); }
-
-function img(src) { return empty("img","src",src); }
-
-/* --- Document modification ------------------------------------------------ */
-
-function clear(el) { replaceInnerHTML(el,""); }
-function replaceInnerHTML(el,html) { if(el) el.innerHTML=html; }
-function replaceChildren(el,newchild) { clear(el); el.appendChild(newchild); }
-
-function appendChildren(el,ds) {
-    for(var i in ds) el.appendChild(ds[i]);
-    return el;
-}
-
-function insertFirst(parent,child) {
-    parent.insertBefore(child,parent.firstChild);
-}
-
-function insertBefore(el,ref) { ref.parentNode.insertBefore(el,ref); }
-
-function insertAfter(el,ref) {
-    ref.parentNode.insertBefore(el,ref.nextSibling);
-}
-
-/* --- Debug ---------------------------------------------------------------- */
-
-function debug(s) {
-    var d=element("debug");
-    if(d) d.appendChild(text(s+"\n"))
-}
-
-function show_props(obj, objName) {
-   var result = "";
-   for (var i in obj) {
-      result += objName + "." + i + " = " + obj[i] + "<br>";
-   }
-   return result;
-}
-
-function field_names(obj) {
-   var result = "";
-   for (var i in obj) {
-      result += " " + i;
-   }
-   return result;
-}
-
-/* --- Data manipulation ---------------------------------------------------- */
-function swap(a,i,j) { // Note: this doesn't work on strings.
-  var tmp=a[i];
-  a[i]=a[j];
-  a[j]=tmp;
-  return a;
-}
-
-function sort(a) {
-// https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Array/sort
-  return a.sort();
-  /* // Note: this doesn't work on strings.
-  for(var i=0;i<a.length-1;i++) {
-    var min=i;
-    for(var j=i+1;j<a.length;j++)
-      if(a[j]<a[min]) min=j;
-    if(min!=i) swap(a,i,min);
-  }
-  return a;
-  */
-}
-
-function filter(p,xs) {
-  var ys=[];
-  for(var i=0;i<xs.length;i++)
-    if(p(xs[i])) ys[ys.length]=xs[i];
-  return ys;
-}
-
-function implode(cs) { // array of strings to string
-  /*
-  var s="";
-  for(var i=0;i<cs.length;i++)
-    s+=cs[i];
-  return s;
-  */
-  return cs.join("");
-}
-
-function hasPrefix(s,pre) { return s.substr(0,pre.length)==pre; }
-
-function commonPrefix(s1,s2) {
-    for(var i=0;i<s1.length && i<s2.length && s1[i]==s2[i];i++);
-    return s1.substr(0,i);
-}
-
-/*
-function all(p,xs) {
-  for(var i=0;i<xs.length;i++)
-    if(!p(xs[i])) return false;
-  return true;
-}
-*/
-
-function map(f,xs) {
-  var ys=[];
-  for(var i=0;i<xs.length;i++) ys[i]=f(xs[i]);
-  return ys;
-}
-
-// map in continuation passing style 
-function mapc(f,xs,cont) { mapc_from(f,xs,0,[],cont); }
-
-function mapc_from(f,xs,i,ys,cont) {
-  if(i<xs.length)
-    f(xs[i],function(y){ys[i]=y;mapc_from(f,xs,i+1,ys,cont)});
-  else
-    cont(ys);
-}
-
-function overlaps(as,bs) {
-    for(var i=0;i<as.length;i++)
-	if(elem(as[i],bs)) return true;
-    return false;
-}
-
-function elem(a,as) {
-    for(var i=0;i<as.length;i++)
-	if(a==as[i]) return true;
-    return false;
-}
-
-function shuffle(a) {
-    for(i=0;i<a.length;i++) swap(a,i,Math.floor(Math.random()*a.length))
-    return a;
-}