A Prototype Proof Translator from HOL to Coq

We describe a low-level proof format, which can be used for independent proof checking and as an intermediate language for translating proofs between systems. The checker is presented as a virtual machine and the proof format as the bytecode. We compare HOL and Coq with a view to designing this pivot language, and describe a prototype which converts recorded HOL proofs into this intermediate format, and then translates them into Coq.