## Section: Application Domains

### Trustworthy implementations of theorem proving techniques

Instead of integrating different provers by exchanging proof
evidence and relying on a back-end proof-checker, another approach
to integration consists in re-implementing the theorem proving
techniques as proof-search strategies, on an architecture that
guarantees correctness. Focused systems can serve as the basis of
such an architecture, identifying points of choice and backtrack and
providing primitives for the exploration of the search space. These
form a trusted *Application Programming Interface* that can be
used to program and experiment various proof-search heuristics
without worrying about correctness. No proof-checking is needed if
one trusts the implementation of the API.

Following the description, in this framework, of quantifier-free techniques such as DPLL(T) [2] , we are now exploring how the architecture can be adapted to accommodate techniques that handle quantifiers. In particular, unification-based or triggers-based techniques [37] , [49] .

This approach has led to the development of the Psyche engine.