Full paper in PDF:
$%H. Ehrig, H.-J. Kreowski, and F. Orejas, Correctness of horizontal and vertical composition for implementation concepts based on constructors and abstractors, Rev. Mat. Univ. Complut. Madrid 10 (1997), no. 2, 365–387.%$

Correctness of Horizontal and Vertical Composition for Implementation Concepts Based on Constructors and Abstractors
Hartmut EHRIG, Hans-Jörg KREOWSKI,
and Fernando OREJAS
Technical University of Berlin
Franklinstraße 28/29
10587 Berlin — Germany
ehrig@cs.tu-berlin.de
Universität Bremen
Postfach 330440
28334 Bremen — Germany
kreo@informatik.uni-bremen.de
Universitat Politecnica de Catalunya
E-08028 Barcelona — Spain
orejas@lsi.upc.es

Received: May 7, 1996
Revised: January 20, 1997
ABSTRACT

A new implementation concept for parameterized specifications based on constructors and abstractors was recently introduced by Orejas, Navarro, and Sánchez which includes most of the implementation concepts in the literature for initial as well as loose semantics. In this paper we redefine vertical and different kinds of horizontal compositions using the new concept of semi-pushout defined for a mixture of signature and specification morphisms. The main results concerning correctness of horizontal and vertical composition are based on new correctness requirements for constructors and abstractors.

1991 Mathematics Subject Classification: 68Q65, 68Q60, 68N05.