Section EqPath.
Variables (n0 : nat) (T : eqType) (e : rel T).
Implicit Type p : seq T.
Variant split x : seq T -> seq T -> seq T -> Type :=
Split p1 p2 : split x (rcons p1 x ++ p2) p1 p2.

Lemma splitP p x (i := index x p) :
x \in p -> split x p (take i p) (drop i.+1 p).