A method and system for formally verifying designs having elements from more than a single design domain is described. An example system allows formal verification of a design containing mixed analog and digital subparts. The system may use different proof engines to solve an appropriate sub-partition of the entire design, and may provide a framework for translating between the different domains to create a unified result. For example, a digital proof engine may be used for a digital only subpart, while an analog proof engine may be used for an analog only subpart. The system may use the partitioning results to determine translators between the various domains, and an order in which the proof engines are applied.