add_tag
Thm.add_tag : tag * thm -> thm
Adds oracle tags to a theorem.
A call to add_tag(tg,th)
returns a th'
such
that calling Thm.tag(th')
returns the tag that is the merge
of the tag associated with th
(if any) and
tg
.
Never fails.
If an oracle implementation wishes to record additional information about the oracle mechanisms that have contributed to the ‘proof’ of a theorem (perhaps the use of existing HOL theorems that will have their own tags), then this function can be used to add that record.