In certain circumstances, an unspoken contract may be established. A contract is implied when the circumstances imply that the parties have entered into an agreement when they have not expressly done so. For example, John Smith, a former lawyer, can implicitly enter into a contract by going to a doctor and being examined; If the patient refuses to pay after the examination, the patient has broken an implied contract. A contract implied by law is also called quasi-contract because it is not actually a contract; Rather, it is a means for the courts to remedy situations in which one party would be unfairly enriched if it were not obliged to compensate the other. The Quanten Meruit claims are an example. With respect to the interpretation of agreements, courts generally apply an objective standard that would be interpreted as a foreigner; not subjective. The (second) restoration of treaties defines the agreement as ”a manifestation of the mutual consent of two or more persons.” (section 3) The UCC defines the agreement as ”the good deal of the parties in fact, as in their language, or by involvement in other circumstances, including trade or the use of trade or efficiency.” The crucial question is what the parties said or did, not what they did or did. An agreement must contain four essential elements to create a contract and its respective obligations: offer, acceptance, consideration and the intention to create legal relationships. If you buy a newspaper, there are all in an instant; In the case of a large-scale transaction, there may be lengthy negotiations leading to a final contract. The basic principle of ”caveat emptor,” which means ”to pay attention to the buyer,” applies to all U.S.
transactions.  In Laidlaw v. The Supreme Court ruled that the buyer did not have to inform the seller of information that the buyer knew could influence the price of the product.  An error is a misunderstanding of one or more contractors and can be relied upon as a reason for the cancellation of the agreement. The common law has identified three types of errors in the Treaty: frequent errors, reciprocal errors and unilateral errors.