spec-constraints

Invariants and preconditions are constraints that hold true throughout system execution or before operations run. This Skill extracts these from requirements and business rules, then generates a validated constraints.yaml file that documents them formally, enabling proof obligations and formal verification of system correctness.

Runtime checks validate constraints during execution; formal proofs verify them mathematically before code runs. This Skill distinguishes between the two, marking which constraints require formal proof obligations versus runtime validation, so you know which guarantees are statically verified.

Yes. This Skill analyzes natural-language requirements and existing artifacts to extract postconditions, laws, and other constraints automatically. It produces a constraints.yaml file with proof obligations, eliminating manual specification work and ensuring completeness.

This Skill generates constraints.yaml following a standard expression language with common patterns for invariants, preconditions, postconditions, and laws. The format is designed for formal systems, making constraints machine-readable and suitable for verification tools.

Constraint specification is essential when you need formal guarantees about system behavior, must prove correctness mathematically, or enforce complex business rules across multiple components. Unlike scattered validation code, formal constraints enable comprehensive verification and catch edge cases before runtime.

No prerequisites are listed. This Skill focuses on defining constraints and marking proof obligations in constraints.yaml. You can use the output with verification tools later, or use it standalone to document formal requirements for your system architecture.