Loughborough University is a top-ten rated university in England for research intensity (REF2014) and an outstanding 66% of the work of Loughborough’s academic staff who were eligible to be submitted to the REF was judged as ‘world-leading’ or ‘internationally excellent’, compared to a national average figure of 43%. In choosing Loughborough for your research, you’ll work alongside academics who are leaders in their field. You will benefit from comprehensive support and guidance from our Doctoral College, including tailored careers advice, to help you succeed in your research and future career. Recent literature has established close connections between existential string logics (based on word equations) on the one side, and query languages for graphs and texts on the other. For each of these models, standard questions are hard to answer: Evaluation is usually at least NP-hard, and static analysis problems are PSPACE-hard or undecidable. This project aims to identify string logics for which these problems become tractable, and to apply these results to query languages and texts and graphs (in particular document spanners and variants of ECRPQs). Hence, the project combines fundamental research in the intersection of logic and combinatorics on words with its application to database theory.