The purpose of a contract is to conclude the agreement reached by the parties and to define their rights and obligations in accordance with this agreement. The courts must apply a valid contract in its current form, unless there is reason to exclude its performance. Illiteracy does not excuse part of the obligation to know the content of a written contract and does not prevent the mutual agreement of the parties. An illiterate is able to give genuine consent to a treaty; the person has a duty to ask someone to read the contract to them and, if necessary, explain it. However, illiteracy can serve as the basis for the annulment of a treaty, if it is considered for other factors such as fraud or overspending. If the person appointed by the illiterate to read or declare the contract is false and acts in accordance with the other contracting party, the contract may be abrogated. An oral contract can also be characterized as a parol contract or an oral contract, a “verbal” signing “spoken” and not “in words,” a use established in British English in terms of contracts and agreements and, more generally, in American English, abbreviated as “cowardly”.  A contract actually implied by the circumstances is a genuine contract, whereas a contract implied by law is in fact a legal obligation that is treated as a contract only for the purpose of an appeal. With respect to the contracts actually implied, the treaty defines the obligation; In the case of quasi-contracts, the obligation imposes the agreement on the parties. There are ambiguities in contractual terms when, after applying the rules or instruments of interpretation, the court cannot make sense of the language used in an agreement or document.
The clear rule is often applied by court to determine whether a contract is ambiguous. If the contract is clear and unequivocal to the judge, there is no need for parol evidence. However, if a writing is ambiguous, the Parol proof is permitted only to illuminate the instrument in the written form, not to vary. A rare type of arrangement that phonologically copies parts of the head instead of agreeing with a grammatical category.  For example, in Bainouk: Also note the agreement that manifests itself in the fact that it is even in a subjunctive atmosphere.