Section RotRcons.
Variable T : Type.
Implicit Types (x : T) (s : seq T).
Canonical seq_eqMixin := EqMixin eqseqP.
Canonical seq_eqType := Eval hnf in EqType (seq T) seq_eqMixin.
Variables (a : pred T) (s : seq T) (A : T -> Prop).
Hypothesis aP : forall x, reflect (A x) (a x).

Lemma eq_all_r s1 s2 : s1 =i s2 -> all^~ s1 =1 all^~ s2.