The plaintiff as lessor brought an action against the defendant lessee for declaratory relief pursuant to section 1060 of the Code of Civil Procedure. The existence of a controversy wаs alleged and placed in issue by the defendant’s answer. The trial court found that a controversy existed as to a proper construction of the terms of the lease, and basing its findings on stipulated facts and the language of the lease, rendered judgment for the plaintiff. The defendant appealed.
The plaintiff owns a department store in the city of Stockton. For about 20 years prior tо March, 1944, one Ben Warshauer operated the shoe department of the store under a lease of a portion of the premises. Mr. Warshauer retired and in his place his brother-in-law, the dеfendant Stanley Girsh, was accepted as the lessee and now conducts the department. A written lease was entered into between the parties on March 7, 1944, providing for the renting of a 20 by 50-foоt space on the mezzanine floor near the stairway, “to be conducted as a Shoe Department,” for a term of five years with option of *679 renewal for a like term. The consideration was specified as 10 per cent of all net cash sales and 11 per cent of all net charge sales. Other provisions regarding payments for utilities, thrift stamps, matters of wrapping and delivery serviсe, management and sales policies, and privilege of window display space were included.
The plaintiff alleges that the defendant claims the sole and exclusive right under the lease tо operate a shoe department in the store. The plaintiff disputes the claim and in turn asserts the right to set up one or more shoe departments in the store in competition with the defendant. On thе trial the court excluded from consideration the defendant’s offer of proof of conversations had between the parties prior to the execution of the lease. The evidenсe was offered as support for an asserted oral understanding that the defendant should have the sole right to conduct a shoe department in the store. The court concluded that the leаse provisions did not amount to a grant to the defendant of the sole and exclusive right to operate a shoe department in the store.
The applicable principles are found in оur codified law. The writing embodies the whole of the agreement between the parties and parol evidence to enlarge or explain it is excluded with certain specified exceрtions (Code Civ. Proc., § 1856), none of which, as will be seen, is applicable here. The function of the court is to ascertain what in terms or in substance is contained in the instrument and not to insert what has been omitted, or to omit what has been inserted. (Code Civ. Proc., § 1858.) Sections 1856 and 1860 permit the judge to place himself in the position of the parties by receiving evidence of the circumstances under which the agreement was made, which in proper cases may explain an extrinsic ambiguity, establish illegality or fraud, or disclose a mistake or imperfection in the writing. There is here no contention that thе language of the lease is ambiguous, that there was any illegality or fraud in the transaction, or any mistaken omission of an agreed provision. Deformation of the lease is not sought. It is not contendеd that there was a collateral agreement for the exclusive right based on a consideration. It is the defendant’s contention that there is implicit in the lease of a portion of the storе for the conduct of a shoe department an agreement on the part of the plaintiff that there would not be another shoe department conducted in the store. This is his contention desрite the fact that such restrictive language is not in the lease and that a declaration to that effect would be *680 to place a restriction upon the plaintiff’s competition with the defеndant and to create a covenant as to the use of the portion of the premises retained by the plaintiff without express provision therefor.
The general invalidity of contractual restraints on trade competition is provided by section 16600 of the Business and Professions Code. However, the prohibition has not been deemed to avoid express restrictive covenants as to thе use of retained premises frequently incorporated in leases. (See
Medico-Dental etc. Co.
v.
Horton & Converse,
A restrictive covenant as to property retained by a grantor or lessor must be evidenced by a clearly expressed intention.
(Wing
v.
Forest Lawn Cemetery Assn.,
The defendant has presented no decision where the cоurt has read in the contract a provision for the restrictive covenant without language to support it. In argument he adopts the word “concession” with reliance on
Belvedere Hotel Co.
v.
Williams,
The question may not be resolved by what the parties might have provided had they thought about it, nor by what the court might cоnclude regarding abstract fairness. The question of what is to be included in the contract is for the parties, not for the court, to determine. Here the defendant seeks to build an implied covenant uрon an inference from the fact that there had always been but one shoe department in the store. The implication however cannot rest solely upon an inference to be drawn frоm the facts surrounding the
*681
execution of the lease. It must have a basis in the contract itself. A condition cannot be read into a contract as to which the parties might well be deemed to havе remained intentionally silent.
(Foley
v.
Euless,
Here, without more, a small portion of a department store was let for the purpose of сonducting “a shoe department. ’ ’ This is not language expressive of an exclusive grant and such a grant is not indispensable to effectuate the expressed intention of the parties. Nor does that or any language of the lease indicate that an exclusive grant was so clearly contemplated that it would be unnecessary to express it. Likewise there is no legal necessity for it, and it might just as well be assumed that had the attention of the parties been brought to it, they would not have agreed to it. The assumption is also readily apparent from the surrounding circumstances that the partiеs thought the time might arrive when one shoe department in the store would be insufficient to supply increased customer demand. It is a matter of common knowledge that many stores have more than one department to supply similar lines of goods. Should the court venture to redecide the question for the parties as a matter of construction contrary to the plain words of the agreemеnt, it might well result in an injustice or inequity which they intended to avoid. This case, therefore, is governed by the well-settled principle that the written memorial of the parties supersedes their prior negotiatiоns and becomes their contract
(Estate of Gaines,
*682
Such questions as when the conduct of another shoe depаrtment by the plaintiff will amount to a breach of the covenant of quiet possession (Civ. Code, § 1927), and constitute a constructive eviction of the defendant in the absence of an express restriction, cannot be determined in this proceeding. A determination of such matters depends upon the facts in a proper case.
(Cf. Lindenberg
v.
MacDonald,
The judgment is affirmed.
Gibson, C. J., Edmonds, J., Carter, J., Schauer, J., and Spence, J., concurred.
Appellant’s petition for a rehearing was denied March 1, 1951.
