Proceedings 18th International Workshop on Logical and Semantic Frameworks, with Applications and 10th Workshop on Horn Clauses for Verification and Synthesis

This volume contains * The post-proceedings of the Eighteenth Logical and Semantic Frameworks with Applications (LSFA 2023). The meeting was held on July 1-2, 2023, organised by the Sapienza Universit\`a di Roma, Italy. LSFA aims to bring researchers and students interested in theoretical and practical aspects of logical and semantic frameworks and their applications. The covered topics include proof theory, type theory and rewriting theory, specification and deduction languages, and formal semantics of languages and systems. * The post-proceedings of the Tenth Workshop on Horn clauses for Verification and Synthesis (HCVS 2023). The meeting was held on April 23, 2023 at the Institut Henri Poincar\'e in Paris. HCVS aims to bring together researchers working in the two communities of constraint/ logic programming (e.g., ICLP and CP), program verification (e.g., CAV, TACAS, and VMCAI), and automated deduction (e.g., CADE, IJCAR), on the topics of Horn clause based analysis, verification, and synthesis.