Formal Methods and Theorem Provers
T-VEC is a formal method.
Formal methods are mathematically-based techniques for the specification, development and verification of software and hardware systems.
T-VEC (behind the scenes is a Theorem Prover) - per the wiki taxonomy
Level 2: Theorem provers may be used to undertake fully formal machine-checked proofs. This can be very expensive and is only practically worthwhile if the cost of mistakes is extremely high (e.g., in critical parts of microprocessor design).