Given two .krb files:
it seems to be necessary to pyke.activate('second') but
then to pyke.prove_n('first', ...).
This seems inconsistent (and required digging to find--some debug functions to display a list of kb and rb namespaces would be helpful).
Also, issuing: pyke.assert('first', .., ..) before the prove_n seems to destroy the 'first' rulebase.