@EriktheOutgolfer that's a nice challege. it took me a while to realise that "surroundings" of the current head means the 6 lines connected to it, not the neighbouring 6 points

@ngn yep, it's detailed more accurately over Wikipedia; the challenge here is to do it in a language with an APL-like syntax

@EriktheOutgolfer i guess k counts as such?

@ngn hey, looks like you did manage to make a 115-byte solution in ngn/k many hours ago! well done :-)

@EriktheOutgolfer thanks. now i should try to explain it too... that may turn out harder than solving it :)

@ngn if I find it impressive enough, I might give it a +50 or +100 unless you don't want to ;-)

@EriktheOutgolfer it wouldn't be fair to other (potentially not yet written) answers...

sometimes i feel like that when i see a rewarded answer

@ngn "might"; I'm currently in bed, let's see tomorrow...

even though I don't think that's really true