  V.I. Arnold [Russian Math. Surveys, 26 (no. 2), 1971, pp. 29-43] gave a
miniversal deformation of matrices of linear operators; that is, a simple
canonical form, to which not only a given square matrix A, but also the family
of all matrices close to A, can be reduced by similarity transformations
smoothly depending on the entries of matrices. We study miniversal deformations
of quiver representations and obtain a miniversal deformation of matrices of
chains of linear mappings.
