Section EqSorted_in.
Variables (T : eqType) (leT : rel T).
Implicit Type s : seq T.

Lemma irr_sorted_eq_in s1 s2 :
{in s1 & &, transitive leT} -> {in s1, irreflexive leT} ->
sorted leT s1 -> sorted leT s2 -> s1 =i s2 -> s1 = s2.