Section EqSortSeq.
Variables (T : eqType) (leT : rel T).
Let pop_stable s1 ss :
push_invariant (s1 :: ss) -> sorted lt_lex (merge_sort_pop leN s1 ss).
End Stability_iota.

Lemma filter_sort T (leT : rel T) :
total leT -> transitive leT ->
forall p s, filter p (sort leT s) = sort leT (filter p s).