Factorio Forums

Hi there,
I feel stupid but I can't understand this spaceship schedule properly. The green square signal is the "OK, I have enough ammo and fuel" so it's safe to leave. Then I want to also leave only if EITHER of purple or orange science is empty. This doesn't look right to me, but I can't seem to group the bottom 2 items such that the logic reads "Green signal > 0 AND (orange = 0 OR purple = 0)"

Is this right as it is? The white line joining the AND and the first OR makes it look like "(Green signal > 0 AND purple =0) OR orange = 0". Am I just reading it incorrectly?

I think you're going to have to duplicate the green signal to do this the way you want:

Green > 0 AND Purple = 0 OR Green > 0 AND Orange = 0

Got it! Thanks.

wobbycarly wrote: Mon Feb 02, 2026 8:28 am Is this right as it is? The white line joining the AND and the first OR makes it look like "(Green signal > 0 AND purple =0) OR orange = 0". Am I just reading it incorrectly?

You're reading it correctly, train/station schedules and decider combinators only support disjunctive normal form (OR on the outside, AND on the inside, no further nesting).
Generally, you can transform your condition into disjunctive normal form (but it'll become tedious with more complicated expressions) and/or move inner ORs into decider combinators (not possible for all conditions).
In this particular case, depending on the requests the station has, "Any request zero" might be useful.