concurs specially as to the ruling announced in the fifth division. The use of the building for moving-picture shows, and acceptance of rents with knowledge of such use and without objection, tends to show mutual assent to departure from the strict letter of the contract, within the meaning of the Civil Code, § 4221; and before the-lessor could sue to enjoin such use, it would be necessary to give reasonable notice of his intention to return to the exact terms of the contract. But such departure *194would not under all circumstances work an estoppel against insistence upon the terms of the contract.