added (a bit ad-hoc) handling of axiom instantiation and equation axiom instantiation, we still fail for the n-tape proof because detection of induction cannot be detected by naive matching (needs an abstraction step)

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1720 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
Fix relating to issue #246. cutIntroduction.Deltas.nub now correctly deletes duplicates.

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1721 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
added toFSequent method to FClause

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1722 85d21ef8-add0-11de-ae77-5bfb9c5a3f34