added "m <= n ==> m-n = 0" [simp]
added "m <= n ==> m-n = 0" [simp]

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