Metis_Examples/Big_O.thy: add number_ring class constraints, adapt proofs to use cancellation simprocs
Metis_Examples/Big_O.thy: add number_ring class constraints, adapt proofs to use cancellation simprocs

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