Seller's Right to Unilateral Termination for Failure to Meet Payment Deadline in Real Property Sale

A contract for the sale of real property, validly formed, was subsequently terminated by the seller after the buyer failed to meet a deadline stipulated in an ancillary agreement for payment of the remaining price, which the seller claimed constituted a resolutory condition precedent to the final conveyance. The court upheld the lower court's decision affirming the termination, reasoning that when a resolutory condition is clearly stipulated in a promise to sell and the defaulting party fails to fulfill the obligation by the specified date, the seller has the right to unilaterally enforce the contract's termination without formal judicial proceedings, provided the other party was duly notified of the deadline's importance.