I mean that programming in a terse language has nothing to do with obscure variable names. The point of terse languages is that knowing the primitives allows you to write concise programs comfortably. It doesn't mean you have to use single letter variables which in opposition to primitives do change between programs.
Well yeah, referring to my above comment the primitives are symbols and it's expected that the user knows them, just as you're supposed to know the keywords in any language.
Good (professional) APL though, will intersperse those primitives with meaningful variable names.
Whether one thinks it's worth the effort to know the symbols vs know the keywords is matter of opinion. But if one dares calling oneself let's say a python programmer, I'd argue that anybody would expect that you'd know the keywords anyways.
