Ok, got it now. I did find another way round this, but I've got another problem now (thanks for your ongoing patience).
From the above I've now got 2 lists as below, iscurrent and offerMadeToViewer. I'm trying to get a 3rd list which shows the overlap between the 2. iscurrent list is [8], offerMadeToViewer is [3,6,8]. So my overlap should be [8].
I've tried both of the following though and am just getting [].
Again any suggestions, and thanks in advance.
Hi ABG thanks there was no way I was going to work that out!
Unfortunately It's still not working. Difference between what you've got and what I've got as below is I'm working from some established precalculated Lists, not set of strings, changed into list with list from csv row text.
Don't think it should make a difference but I'm still getting [] as my final result. Can you have a look at the following and see if I've stuffed up anything?
and
I advise applying Do It to both inputs to the value procedure, then to the value procedure call.
Show us the results?
Also, feeding output back into an input fouls up debugging.
Ok to clarify by 'Do It' you mean the purple procedure block - to procedure do ?
If so I'll work on this with the 'iscurrent' and 'offerMadeToViewer' variables.
Also could you clarify 'feeding output back into an input fouls up debugging'?
thanks
Extra global variables can be used to hold intermediate calculation results unsullied for later examination.
Did you notice the bubble on the screen shot of my sample call?
That's an MIT AI2 debug facility, in the introductory section off the debugging FAQ.
Make your blocks look like a pincushion with Do It bubbles.
OK, I'll read up on Do it bubbles and get back to you, might be a couple of days.
Again thanks for your help 
Hi again, sorry when I right click on the various blocks 'Do It' is either not there, or greyed out.
Any suggestions?
You have to have started and connected to the MIT Companion app.
Running it on your phone is the fastest and easiest.
Hi
I am using the Companion App, but not the emulator.
Good.
Use the Connect->Companion option, and scan the code to complete the connection. Then you can set the phone down (I charge it) and apply Do Its in the Blocks Editor (after entering required inputs as needed)
Ok don't know what happened there, wasn't working before but is now. I'll have a go with it. Thanks again.
Hi again, I've got the following code and as you can see the Do It block on the a result of [9] which is correct, but when I try to display this using the volume text label i just get an empty string.
Any suggestions.
thanks
You executed the calculation of the Intersection using Do It, but you failed to apply Do It to the block that sets the value of that global variable?
Likewise for the next pair of blocks, that set the volume.Text value?
Is this what you mean? Or do you mean the currentOfferedToViewer and volumeText blocks need to have Do It done to them. If so I'm clicking on these 2 blocks getting the menu and clicking Do It but nothing happens. Is that because I already have Do It activated in a subsidiary block. If so how do I Undo Do It on those blocks?
thanks
Ok just tried hitting Do It for the volume text block and the correct result showed. will this happen automatically now each time it runs?
no
each time you have to click Do it again
Taifun
Do It is like a doctor hitting your knee with a rubber hammer to check your reflexes.
It's a one shot deal.
Hopefully, your knee works okay when you walk, without the doctor having to chase you down the street with his hammer.
