chop()
If you can teach chop() using chop on Zara's board, you know it. If you only know the heading, you don’t.
Do chop() once by hand. one chop step Zara can write from memory. Change one input. Say the new result out loud.
chop() exists so Zara can keep chop on Zara's board correct in a first job task.
Use chop() when chop on Zara's board must stay clear. If a simpler PHP step works, use that instead.
If chop on Zara's board breaks under chop(), check copy-pasting chop without a dry-run first.
Place chop() next to nearby PHP work — one chop step Zara can write from memory is the link.
One breath for chop(), then chop on Zara's board, then copy-pasting chop without a dry-run. Sit down.
For chop(): definition + a first job task + one failure.