proposition: Lemma is_cvg_restrict f u_ : cvgn [sequence if (n <= N)%nat then f n else u_ n]_n = cvgn u_.
proof: Proof. by rewrite propeqE; split; [rewrite cvg_restrict|rewrite -(cvg_restrict f)] => /cvgP. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(set_interval) reals ereal signed topology normedtype landau