Trained as a mathematician, I developed an interest in prolog in grad school and have been both exploring and applying its capabilities my whole career spanning five decades -- mostly in network design but branching out over time.  For personal use, I developed tennis Blocktime and Matchplay scheduling apps and swim coach advisor tool about 20 years ago.  

My personal research in optimization is centered around the theory and implementation of my St*Mesh network restoration planning tool, motivated by interval constraint solving.. Since then, variations of this approach have been successfully applied to optical mesh restoration design, optical connection planning, and task scheduling.  

The tennis scheduling apps use a combination of prolog and Constraint Handling Rules (CHR), with SWI Prolog's XPCE GUI builder.  Overall, prolog code performs  the generation and search for solutions;  CHR describes and enforces constraints that user may impose on solution feasibility.