I think you're offering a very particular case with a well-known idiomatic presentation and trying to apply it to the general case. In this case a, b, x, and y

I think you're offering a very particular case with a well-known idiomatic presentation and trying to apply it to the general case. In this case a, b, x, and y are both letters and good variable names for their purpose because of their long, familiar use in mathematics. But calling your main GUI window "m", your data "d", and your server connection object "b" doesn't make for readable code.