PREVAIL: A proof environment for VHDL descriptions The authors describe a formal verification environment for proving the equivalence of two VHDL architectures of the same design entity, provided the designer conforms to some restrictions in the description style. For simple bit-level combinational descriptions, the environment calls upon a tautology checker. For parameterized repetitive structures, and designs described at a more abstract level, the descriptions are translated into recursive functions, according to pre-defined templates, and a theorem is generated in a form acceptable by the Boyer-Moore theorem prover. For well identified classes of circuits, the proof is fully automatic.