[abrudz]

That's actually a historical quirk, because modern keyboards have = where old APL keyboards had × and - where old APL keyboards had +. You'd press Shift+ for - and Shift× for ÷ meaning that Shift gives the inverse function. Similarly, they Shift/ for \ (which is the inverse of / in APL).

See https://en.wikipedia.org/wiki/APL_(programming_language)#/me...