PROCEEDINGS OF THE IFIP TC10/WG10.2 INTERNATIONAL WORKSHOP ON HIGHER-ORDER LOGIC THEOREM-PROVING AND ITS APPLICATIONS - HOL 92 ORGANIZED BY CHEOPS ESPRIT BRA 3215 SPONSORED BY IMEC AND THE COMMISSION-OF-THE-EUROPEAN-COMMUNITIES LEUVEN, BELGIUM, 21-24 SEPTEMBER 1992 - PREFACE