Go to URL jseden.dcs.warwick.ac.uk/nick/
It opens with two windows Canvas Picture and Script View under a black bar with some menu headings written in white.

Go to window Script View, find the menu icon bottom right (like grey traffic lights), left click and choose Browse Agents. Left click person icon for agent 'c6' (may need to scroll down list), left click on person icon for 'givingchange' then click in the box for 'versions1and2' (may need to wait for appearance) then click the green 'Add' button bottom left.

You will see two groups of 'import' statements. We use the second group (version2). But before we use that find the following import statement at the very bottom of the file after scrolling down:
 import givingchange/commentary2;
Put your cursor in the left margin level with this statement. Click on the 'arrowhead' symbol that appears. A commentary will appear in the background under the Canvas window. There is a lot to read in the commentary so in the presentation we now take several short cuts.

Make the Canvas window only about an inch or so high, go to Options menu and choose 'Hide windows on minimize'. Minimize the Canvas (can get it back from Existing Windows). Read through first few slides of commentary2 explaining how we have identified some observables and their dependencies. Reach the first slide with some 'embedded windows' and try selecting groups of definitions in the left margin (producing a blue bar) which can be loaded (briefly a green line appears confirming this). One such definition opens the Symbol List with some observables, including coinlist. Keep that visible.

Now we leave the commentary so you can leave Symbol List covering the commentary and bring out the Canvas from the Existing Windows list, place it under the Symbol List. It will just have the CONSTRUIT! logo at present.

From here the main action will occur in the Script View (or as it is now headed, 'Agent'). You are probably at the bottom of the file where you loaded commentary2. Click in that window and scroll up to have the five import statements for version 2 in front of you. Go to the Inspect icon (magnifying glass) at the bottom of that window and left click. Select the line 'import givingchange/concisemodel' and leftclick, it will show the script and a tab 'concisemodel'. Right-click on the tab (maybe ctrl-click on a Mac touch pad) and choose 'Run(force)'. The person icon in tab goes green. Repeat for the four other import statements (... action, init, defnpicture, basicvisual). At this point the 'amount' observable showing in the Symbol List window should still be 8. Click in the Canvas and a 5p coin should appear, and a '5' in the coinlist above. Two more clicks give the rest of the 8p change. Click on the 'action' tab in the Agent window and you probably will not have much trouble understanding what happened with your clicks.

Finally, modify the action script by commenting out the line 'click is mousepressed;' (two hash symbols like other comments), delete the '&& click' (but not the right parenthesis!) and delete the 'wait 100;'. Now go to the 'init' tab and select in left margin the five lines from '{' to '}' and load them (left click blue bar). You should see the change lists change immediately. For a more dramatic display go to the line of 'amount' in 'init' and click and hold cursor in left margin for a few seconds, the arrow head will change to a red asterisk. Click on the value '195' and slide cursor right or left - it has become a slider bar changing the values immediately. The corresponding coinlists are generated in real time.