OK, I've worked this out. But it turns out that if you flip a user defined function you also invert the x and y inputs - i.e. normally x is the upper input but, when flipped, it is the lower one. I've created a ticket about this.
Flipping user defined function inverts inputs
What is the protol for user defined functions? To keep things simple, if I have constants one (1) and two (2) wired to the inputs of my user defined function (mysum), what do I put as the expression to get the output 3?
I want to make a donation via bank transfer, but my financial institution will not accept "KeePass" as the account name. It says it is incomplete or contains illegal characters. Is there a fuller or more formal name?