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.

翻译：本卷收录了以下内容：* 第十八届“逻辑与语义框架及其应用”（LSFA 2023）的会后论文集。该会议于2023年7月1日至2日举行，由意大利罗马大学（Sapienza Università di Roma）组织。LSFA旨在汇聚对逻辑与语义框架的理论与实践层面及其应用感兴趣的研究人员与学生。涵盖主题包括：证明论、类型论和重写理论、规约与演绎语言，以及语言和系统的形式语义。* 第十届“Horn子句验证与综合研讨会”（HCVS 2023）的会后论文集。该会议于2023年4月23日在巴黎亨利·庞加莱研究所（Institut Henri Poincaré）举行。HCVS旨在汇聚来自约束/逻辑编程（如ICLP和CP）、程序验证（如CAV、TACAS和VMCAI）以及自动演绎（如CADE、IJCAR）三个领域的研究人员，共同探讨基于Horn子句的分析、验证与综合等主题。