{R : Ring@{i}} {n : nat} (v : Vector R n) : Matrix R n n. Proof. snrapply Build_Matrix. intros i j H1 H2. exact (kronecker_delta i j * Vector.entry v i). Defined.
Require Import Basics.Overture Basics.Trunc Basics.Tactics Basics.Decidable. Require Import Types.Sigma. Require Import Spaces.List.Core Spaces.List.Theory Spaces.List.Paths. Require Import Algebra.Rings.Ring Algebra.Rings.Module Algebra.Rings.CRing Require Import abstract_algebra. Require Import WildCat.Core WildCat.Paths. Require Import Modalities.ReflectiveSubuniverse.