I think I might be looking at too much FVWM configurations. The code has stopped making sense to me. And there doesn’t seem to be a good place to get help.
The latest problem is in the online man page:
Grow the focused window towards the top of screen
Current Resize keep w+$[w.y]p keep 0
This doesn’t do what is says. And I don’t think anything has been done to the man page for years, so I don’t know if this is another bug or if the example is wrong.