  Suppose we have been sold on the idea that formalised proofs in an LCF system
should resemble their written counterparts, and so consist of formulas that
only provide signposts for a fully verified proof. To be practical, most of the
fully elaborated verification must then be done by way of general purpose proof
procedures. Now if these are the only procedures we implement outside the
kernel of logical rules, what does the theorem prover look like? We give our
account, working from scratch in the ProofPeer theorem prover, making
observations about this new setting along the way.

Logic in Computer Science