Summary

Similar to this report about burner miners when I initially place burner inserters they briefly work before "running out of fuel" despite never having been fuelled and the source items not being burnable.

What did you do?

Seen in other scenarios but quick recreation steps that so far ...

I have to agree with everyone above being confused by the logic parsing.

Although I am all for the indentation proposal I do wonder if there is reinventing the wheel a bit here, after all there is already a logic/combinatorial system in Factorio:

Circuit Network

But actually using this in a train ...

Searched and couldn't see an obvious topic on this. Not necessarily a bug but thought I'd bring it up for discussion.

Summary
You can research Artillery, and therefore have access to make artillery shells, without having researched the components that are required to make an artillery shell ...