applies to the bankruptcy court’s severance of these counterclaims. In its motions to sever, Kaiser moved under Bankruptcy Rules 7012, 7013, 7021 and 7042. Bankruptcy Rules 7012 and 7013 do not address the severance of claims or counterclaims. Rule 7012 simply provides for the form and time periods for filing answers and answers to cross-claims and for the admission or denial of the designation of core and non-core matters. Bankruptcy Rule 7013 is similarly unhelpful. While it concerns the filing of counterclaims and cross-claims, the rule does not cover their severance. The rule simply makes Fed.R.Civ.P. 13 applicable to bankruptcy adversary proceedings, with the exception that a party sued by a debtor in possession or a trustee need not state as a counterclaim any prepetition claim (<HOLDING>). See Bankr.R. 7013 editors’ comment. Kaiser
holding claimant waived right to jury trial on claims brought against it on behalf of bankruptcy estate when it submitted its proof of claim against the estate and subjected itself to the equitable powers of the bankruptcy court holding that when the claim was duly established as a valid claim against the estate the laws of limitation could no longer apply while the estate was being administered under the probate law holding that a lawsuit by a third party creditor against the estate is a core proceeding holding that bank as coexecutor of estate breached its fiduciary and statutory duties to creditor when it failed to pay creditors claim against estate and instead paid claims of bank and other creditors recognizing that the party can instead file a claim against the estate