fact: Definition Jordan_block lam n : 'M[R]_n := \matrix_(i,j) (lam *+ (i == j :> nat) + (i.+1 == j)%:R).
imports: mathcomp(all_ssreflect) mathcomp(all_algebra) mathcomp(all_fingroup) mathcomp(all_real_closed) CoqEAL(binetcauchy ssrcomplements mxstructure minor) CoqEAL(smith dvdring polydvd) CoqEAL(similar perm_eq_image companion closed_poly smith_complements) CoqEAL(frobenius_form)