Sort search results in order of relevance, where relevance =
a) better if 0 premises for intro or 1 premise for elim/dest rules
b) better if substitution size wrt to current goal is smaller
Only applies to intro, dest, elim, and simp
(contributed by Rafal Kolanski, NICTA)
use "../settings";
use_thy "termination";
use_thy "Induction";
use_thy "Nested1";
use_thy "Nested2";