diff --git a/slides/access-trees.html b/slides/access-trees.html
index a4b35e1594b3cc0a6ac1993ca52305b19f2e6494..172d490938f1c7b47668303cfad5250a45121d2d 100644
--- a/slides/access-trees.html
+++ b/slides/access-trees.html
@@ -213,24 +213,6 @@ Easy to split this up among a group
      `<link href=“style.css” rel=“stylesheet” />`
 - Great example is [CSS Zen Garden](http://www.csszengarden.com/)
 
-<!-- --- -->
-<!-- # CSS -->
-
-<!-- .left-column50[ -->
-<!-- - Files consist of one or more rule sets -->
-<!-- - Each rule set has a selector which chooses which HTML elements you want to style -->
-<!-- - Style properties are set with rules which are  property/value pairs -->
-<!-- - Syntax is important -->
-<!-- - More on [CSS](https://developer.mozilla.org/en-US/docs/Web/CSS) -->
-
-<!-- ] -->
-
-<!-- .right-column50[ -->
-<!-- ![:img CSS rules description, 100%, width](https://code.makery.ch/library/html-css/part3/css-rule.png) -->
-
-<!-- From [W3Schools](https://code.makery.ch/library/html-css/part3/) -->
-<!-- ] -->
-
 ---
 # Layout in CSS
 
@@ -256,7 +238,6 @@ fortunately there is CSS [Flexbox](https://courses.cs.washington.edu/courses/cse
 
 ]
 
-
 ---
 # Document Object Model (DOM) (2/3)
 
@@ -315,17 +296,17 @@ linkStyle default stroke: black,stroke-width:8px
 **Interface Programmers** combine *library elements* (e.g. buttons and labels) according to *toolkit rules* &
 constraints of *toolkit architecture* (common to all UI toolkits). Example: let's list all the components of this image:
 
-
 ![:img Picture of a very simple interface showing a ringing bell at
 left and an x at right to close the window with the words Google
 Calendar reminder Christian and Anind (Jen Mankoff) is starting at
 12:30pm. Video call between them, 100%, width](img/building/interface.png)
 ]
 .right-column50[
-Discussion (post on Ed)
+Discussion (post on [Ed]({{site.discussion}}/3666535))
 - What are the "components" in this image?
 - What does the "interactor hierarchy" look like for this image
 ]
+
 ???
 discuss with your neighbor
 - what to draw; where to draw it