[benplumley]

That's a coincidence, that the author only picked recipes that are made without cycles. Other Factorio recipes (e.g. nuclear fuel processing) are cyclic.

[perihelions]

There aren't any other ingredient cycles in unmodded Factorio (besides the trivial barrelling/un-barrelling of fluids).

[benplumley]

I thought you could go between heavy and light oil cyclically, but I think the recipes I'm thinking of are from UltraCube. The others are a subset of nuclear (Kovarex and reprocessing), so I think you're right.