From Jason Reed:

Essentially all of the components of the theorem prover have been written.
We are now in the debug/test phase. The write-up still needs more polish
and more information about rule generation, but it is partly finished.

Several bugs were found recently, and currently we have a perfect record
on the propositional subset, but several dissimilar first-order
propositions produce "impossible" exceptions or proofterms which don't
type-check. Since many of the components seemed to be okay under isolated
testing, we expect and hope the remaining bugs aren't too deep.