Article 84 of the Contract Law provides for the contract of assumption of debts concluded between the debtor and the
assumer, which is different from the way in which the creditors are directly involved from the aspect of logical structure
and trading habits. For the foundation of doctrine of Article 84, it is necessary to integrate the different systems
including unauthorized disposition and contract in favor of the third party. On this basis, the various factors involved in
the operation of Article 84 could be researched profoundly, including the agreement of assumption of debts, the creditor's
consent, the cause of assumption, the rights to defense of the assumer, the continuation of the guarantee, and so on to make
the application of law precise.