Proof of debt: trustees must notify creditors to submit specified claims and may value unquantified debts for distribution. Proof of debt requires the bankruptcy trustee to notify creditors to submit claims in prescribed form with full particulars of debt and security; decree holders may submit a copy of the decree; interest is provable only up to the bankruptcy commencement date; the trustee estimates unvalued debts and that estimate governs the amount provable; creditors with post commencementdue debts may prove as if presently owed and share in dividends; secured creditors who fail to file proof may lead to trustee, with leave, disposing of the secured property free of security.