In the J language, the verb `over` doesn't work

Question

I'm following along this thing: J Dictionary

It tells me to issue the command d by d over d!/d where d is a list, but my jqt environment tells me value error: over. If the problem is that I'm supposed to import/install/activate a library, I don't see any instructions in the documentation about that. Anyone know what's going on here?

Answer 1

From the documentation you linked:

The verbs over=:({.;}.)@":@, and by=:' '&;@,.@[,.] can be entered as utilities (for use rather than for immediate study)

It's telling you to define those verbs in order for the following code to work.

So they're not part of the standard library nor any other library - you're supposed to define them yourself.