It may happen when one directly translates into code an algorithm, a concept, or a formula from mathematics, physics, or computer science theory, where all the

It may happen when one directly translates into code an algorithm, a concept, or a formula from mathematics, physics, or computer science theory, where all the symbols are terse, you're supposed to have read a hefty book or stack of papers where those are introduced, and the author laments the demise of APL with all the nifty symbols it had. Oh, and you're fully expected to speak their argot fluently, of course, otherwise you're a castaway to be thrown stones at.