If you could also incorporate precedence rules you could get some more reduction. e.g. for the h1,h2 example, you'd have a selector for `h1,h2` (which is essent

If you could also incorporate precedence rules you could get some more reduction. e.g. for the h1,h2 example, you'd have a selector for `h1,h2` (which is essentially the full h2 rules) and another for `h1` that overrides the font-size. Then when needing to "reduce" rules you could select for "smaller" rules and the only loss would be that h1 and h2 have the same size. To do that I think you'd need to do the factorization on the CSS properties alone, and then apply the values in a predetermined order. But would be cool/fun to test out!