Types and Programming Languages.- From Rewrite Rules to Axioms in the lambdaPi-Calculus Modulo Theory.- Light Genericity.- Logical Predicates in Higher-Order Mathematical Operational Semantics.- On Basic Feasible Functionals and the Interpretation Method.- Logic and Proofs.- Succinctness of Cosafety Fragments of LTL via Combinatorial Proof Systems.- A Resolution-Based Interactive Proof System for UNSAT.- Craig Interpolation for Decidable First-Order Fragments.- Clones, closed categories, and combinatory logic.- Infinite-State Systems.- Reachability in Fixed VASS: Expressiveness and Lower Bounds.- From Innermost to Full Almost-Sure Termination of Probabilistic Term Rewriting.- Dimension-Minimality and Primality of Counter Nets.- Parameterized Broadcast Networks with Registers: from NP to the Frontiers of Decidability.

The two open access volumes LNCS 14574 and 14575 constitute the proceedings of the 27th International Conference on Foundations of Software Science and Computation Structures, FOSSACS 2024, which took place in Luxembourg in April 2024.The 24 full papers included in this book were carefully reviewed and selected from 79 submissions. They were organized in topical sections as follows: Part I: Infinite games; categorical semantics; automata and synthesis; Part II: Types and programming languages; logic and proofs; infinite-state systems.

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