Comment 8 for bug 1024362

The OP adds the idea of reading a leading + or - as relative change (more or less). While that is not a good idea because you would not be able to enter negative measures or to copy-paste values with leading + into the fields, I suggest to use a leading @ as indicator for a relative change. @ would behave similar to the suggested l variable but additionally allow inputs such as @2cm instead of l+2cm to move 2 cm starting from the old coordinate. Yes, some convenience thing, so the @ could be subject of discussion, but don't do the leading binary operator magic and please do the variables :-D.