metaconstraint

Metaconstraint is a higher-order constraint that governs the creation, selection, and enforcement of other constraints within a system. It operates at a meta-level, specifying how constraints themselves should be formulated, combined, prioritized, and checked. In constraint programming and optimization, metaconstraints are used to control the search process, limit the growth of the constraint set, and enforce properties such as tractability, recoverability, or safety. For example, a metaconstraint might require that any added constraint be non-redundant with existing constraints, or that the cumulative effect of constraints does not exceed a predefined complexity bound. Metaconstraints can also encode preferences or priorities, guiding solvers toward solutions that satisfy higher-order criteria.

In other domains, metaconstraints appear where decisions about which normative constraints to impose are themselves subject to criteria. They may serve to ensure interpretability, accountability, or consistency across systems that use multiple constraints. The term is used in various disciplines with overlapping meanings, and there is no universally fixed definition. It is related to, but distinct from, meta-constraints or higher-order constraints in logic and philosophy, which emphasize reasoning about rules themselves rather than the specific domain constraints.

Related terms include constraint satisfaction problem, constraint programming, meta-constraint, and higher-order logic.