I don't need you to be able to deduce what the J is doing. What I need is to write the computation as fast as possible so I can get the answer I need to know and then get back to whatever else I was doing. If I was writing something I needed to share with someone else, for sure I wouldn't use J!
> import math prod([math.factorial(x) for x in l]) No! Bad python! In J it’s just / ! l, quite literally an order of magnitude fewer keystrokes.
I don't know anything about `match.factorial()` or `prod()` but I can deduce what it's doing. `/ ! l` is nonsense.