proposition: Lemma nth_take_dflt (n0 : nat) (T : Type) (x0 : T) (i : nat) (s : seq T) : nth x0 (take n0 s) i = if n0 <= i then x0 else nth x0 s i.
proof: Proof. case: (leqP n0 i) => Hi; last by rewrite nth_take. by rewrite nth_default // size_take; case: ltnP=>// H'; apply: leq_trans H' Hi. Qed.
imports: Coq(Rdefinitions Raxioms RIneq Rbasic_fun) mathcomp.ssreflect(ssreflect ssrfun ssrbool eqtype ssrnat seq bigop) MathComp1or2