(delete-theory-and-children [<theory>] [<implementation>]
Deletes the specified theory and all theories which include it, recursively. Theories which are included by theories being deleted will be unincluded prior to deletion. Returns T if at least one appropriate theory was found and deleted, nil otherwise. See also DELETE-THEORY.
<theory> may be any object acceptable to FIND-THEORY. If unspecified, the current theory is assumed (see IN-THEORY and *CURRENT-THEORY*.)
<implementation> is the name of an implementation, as given to IN-IMPLEMENTATION. It is used to disambiguate the <theory> argument if that theory is given as a symbol.