Section EqSorted.
Variables (T : eqType) (leT : rel T).
Implicit Type s : seq T.
Local Notation path := (path leT).
Local Notation sorted := (sorted leT).
Hypothesis leT_tr : transitive leT.

Lemma sorted_ltn_index s :
sorted s -> {in s &, forall x y, index x s < index y s -> leT x y}.