This volume contains the proceedings of the fourthInternational Joint Conference on the Theory and Practice ofSoftware Development, TAPSOFT '93. Since the first in 1985,the aim of these conferences has been to bring togethertheoretical computer scientists and researchers in softwareengineering with a view to discussing how formal methods canusefully be applied in software development.TAPSOFT '93 consists ofthree parts: an advanced seminar,the Colloquium on Trees in Algebra and Programming (CAAP),and the Colloquium on Formal Approaches of SoftwareEngineering (FASE). The advanced seminar includes fourinvited surveys and four invited conferences. The selectedpapers for CAAP are organized in seven sessions:specifications and proofs, concurrency, automata andcounting, constraints solving, rewriting, logic and trees,analysis of algorithms, and a common session with FASE ontype inference. The selected papers for FASE are presentedin eight sessions: case studies in formal design anddevelopment, compositionality modules and development,formal development, foundations and analysis of formalspecifications, verification of concurrent systems, modelchecking, parallel calculus, and a common session with CAAPon type inference.

This volume contains the proceedings of the fourthInternational Joint Conference on the Theory and Practice ofSoftware Development, TAPSOFT '93. Since the first in 1985,the aim of these conferences has been to bring togethertheoretical computer scientists and researchers in softwareengineering with a view to discussing how formal methods canusefully be applied in software development.TAPSOFT '93 consists ofthree parts: an advanced seminar,the Colloquium on Trees in Algebra and Programming (CAAP),and the Colloquium on Formal Approaches of SoftwareEngineering (FASE). The advanced seminar includes fourinvited surveys and four invited conferences. The selectedpapers for CAAP are organized in seven sessions:specifications and proofs, concurrency, automata andcounting, constraints solving, rewriting, logic and trees,analysis of algorithms, and a common session with FASE ontype inference. The selected papers for FASE are presentedin eight sessions: case studies in formal design anddevelopment, compositionality modules and development,formal development, foundations and analysis of formalspecifications, verification of concurrent systems, modelchecking, parallel calculus, and a common session with CAAPon type inference.