added case for handling 'assumption' lines in Satallax proofs;
added case for handling 'assumption' lines in Satallax proofs;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle