R. S. PHILLIPS I am very gratified to have been asked to give this introductory talk for our honoured guest, Israel Gohberg. I should like to begin by spending a few minutes talking shop. One of the great tragedies of being a mathematician is that your papers are read so seldom. On the average ten people will read the introduction to a paper and perhaps two of these will actually study the paper. It's difficult to know how to deal with this problem. One strategy which will at least get you one more reader, is to collaborate with someone. I think Israel early on caught on to this, and I imagine that by this time most of the analysts in the world have collaborated with him. He continues relentlessly in this pursuit; he visits his neighbour Harry Dym at the Weizmann Institute regularly, he spends several months a year in Amsterdam working with Rien Kaashoek, several weeks in Maryland with Seymour Goldberg, a couple of weeks here in Calgary with Peter Lancaster, and on the rare occasions when he is in Tel Aviv, he takes care of his many students.

Inhalt
Editorial Preface.- A: The Calgary Conference, honoring Israel Gohberg.- Portrait I. Gohberg.- Acknowledgements.- The Calgary Conference Program.- B: Papers on Matrix Theory and its Applications.- Some matrix inequalities in multiport network connections.- Complementary triangular forms of upper triangularToeplitz matrices.- Comparing a matrix to its off-diagonal part.- Ranks of completions of partial matrices.- Finite dimension problems in operator theory.- Matrices with displacement structure, generalized Bézoutians, and Moebius transformations.- Generalized Gohberg-Semencul formulas for matrix inversion.- Variational properties and Rayleigh quotient algorithms for symmetric matrix pencils.- The matrix quadratic equation and factorization of matrix polynomials.- Inversion of partially specified positive definite matrices by inverse scattering.- Fast and efficient parallel inversion of Toeplitz and block Toeplitz matrices.- Stability of invariant lagrangian subspaces II.- On strong ?-stability of invariant subspaces of matrices.- On classification of invariant subspaces of a linear operator.- On the inverse of block tridiagonal matrices with applications to the inverses of band matrices and block band matrices.- Divisibility relations satisfied by the invariant factors of a matrix product.- Duality methods for the boundary control of some evolution equations.- Unitary extensions of isometries and contractive intertwining dilations.- Factorization and general properties of nonlinear Toeplitz operators.- Quasilocal algebras over index sets with a minimal condition.- The analogue of Kuroda's theorem for n-tuples.- The geometry of representing measures and their critical values.- Boundary element analysis of a direct method for the biharmonic Dirichlet problem.-Nonlinear lifting theorems, integral representations and stationary processes in algebraic scattering systems.- Characteristic functions of unitary colligations and of bounded operators in Krein spaces.- Differential operators of fractional order and boundary value problems in the complex domain.- On reproducing kernel spaces, J unitary matrix functions, interpolation and displacement rank.- On asymptotic Toeplitz and Hankel operators.- Iterative commutant lifting for systems with rational symbol.- On the reduction of coercive singular perturbations to regular perturbations.- Averaging techniques for the transport operator and an existence theorem for the BGK equation in kinetic theory.- Factorization of nonlinear system.- Minimal lower separable representations: characterization and construction.- On the inclination of hyperinvariant subspaces of C11-contractions.- Unimodular Möbius-invariant contractive divisors for the Bergman space.- Trigonometric approximation of solutions of periodic pseudodifferential equations.- Wiener-Hopf factorization of certain non-rational matrix functions in mathematical physics.- Classes of operator monotone functions ans Stieltjes functions.- A unified approach to function models, and the transcription problem.- Quadrature methods for strongly elliptic Cauchy singular integral equations on an interval.- General Wiener-Hopf operators and representation of their generalized inverses.- Exposed points in H1, I.- Geometrical properties of a unit sphere of the operator spaces in Lp.- C*-algebras of Crystal groups.- On Wiener-Hopf determinants.