16 17. 18. 19. 20. 21. 22. 23. 24. 25. . Each one of the solidary creditors may do may do whatever maybe useful or beneficial to the others as well as anything which may be prejudicial to the latter. As a general rule, a solidary creditor can assign his rights based on the principle of transmissibility of rights. Solidarity makes a solidary obligor an indispensable party in a suit filed by the creditor. When the law expressly provides for solidarity of the obligation, each obligor may be compelled to pray prorata the obligation. Suretyship is merely a principal obligation. A surety is not considered in law to be on the same footing as the principal debtor in relation to whatever is adjudged against the latter. A surety who pays the creditor has the right to recover that full amount paid from the principal debtor or debtors. The penalty shall substitute the indemnity for damages and the payment of interest in case of nonvcompliance. A principal obligation may exist without an accessory obligation but an accessory obligation cannot exist without a principal obligation. An accessory obligation is not dependent for its existence on the existence of a principal obligation