Clauseway

A logic programming stack for real problems. Clauseway is a Java library family for writing programs as relations: unification, finite-domain constraints, tabling and weighted inference over real data sources — SQL databases included — with transactional writes and pinned, reproducible reads.

The stack

Part	What it is
functional	The substrate: fibers, fair schedulers, continuations — the machinery that keeps relational search complete and debuggable.
logic	The engine: unification, constraint stores (finite domains, disequality, nogoods), tabling with constraint-aware answer caching, weighted inference.
pldb	The data boundary: relations backed by in-memory or SQL sources, constraint pushdown into WHERE clauses, transactions that certify their reads.
library	The worked example: a lending-library domain built entirely from rules — policies as relations, denials as their complement.

Why

Most business logic is relations wearing imperative costume. Clauseway exists to let the relations speak for themselves: a rule is stated once and runs in every direction — computing due dates, inferring checkout days, or refusing inconsistent data — over types that matter and data that lives in a real database. The full argument is the opening essay: The half of the Tar Pit we skipped.

Where to start

• The blog — development notes along the way, opening with the essay that explains why this stack exists.
• The repositories above — each part builds with plain Maven.