Yarai › Conflict library
Every pairwise conflict rule in Yarai's engine, with its severity, the chemical mechanism, the evidence tier behind it, and the condition that makes it actually apply. Plus the pairs we're asked about constantly and deliberately don't flag, with the reason for each.
These pages are generated from the same rule file the app runs on, so a page here cannot say something the scanner in your pocket disagrees with.
Note what is not in that list: nothing graded "don't combine." Every pair above is a timing problem, not a compatibility wall. The honest version of this topic is much less dramatic than the search results suggest, and the fix is almost always to move something to another night rather than to throw it away.
A conflict engine is only as trustworthy as its willingness to say no. These pairs are widely repeated as conflicts. We looked, and the evidence doesn't hold. Two of them were rules we shipped and then removed.
Every page here answers one pair. Your routine is not one pair. If you use four active products, there are six pairs to check, and the answer to each one changes what you do about the others. Yarai does that arithmetic across your whole shelf, morning and evening, with the same graded rules and the same sources shown in the app.