Legal and jurisprudential Scrutiny of Substance and Effects of appearance of right of cancellation in case of non-payment of price in sale contract

Occasionally, there is a condition as a sale contract in which, if the buyer has a violation in paying the price, the seller has the right of cancellation of the contract. One could ask what is the substance of this condition and its option and what is the effect of the condition? Are a contract with a transfer nature that the buyer concludes is valid? If the seller rescinds the first contract by virtue of a violation by the buyer, is the restitution of the object of sale in a subsequent contract possible? By analytical-descriptive method and from legal and jurisprudential view, this research tries to come out answers to these questions and scrutinize Supreme Court No.810. This research shows that the description of the above-mentioned condition as the condition of option and option of the unfulfilled condition have fewer objections. Of course, the decision is silent about it. Although there are different legal and jurisprudential views about the effect of condition on subsequent contracts, the subsequent contracts are valid unless otherwise inferred from the reflected intention of the parties of the first contract. According to the decision, the restitution from subsequent assignees is subject to the parties' intention to the first contract.