In James G. Freeman & Associates, Inc. v. Tanner (1976) 56 Cal.App.3d 1, section 1698 was not asserted as a defense; and the trial court did not base its findings and conclusions on oral modification of a prior written agreement. Rather, it found that the contemporaneous oral agreement consisted of the written document and an agreement to redraft a paragraph thereof. The court held that parol evidence may be admitted to prove the elements of an agreement not reduced to writing so long as the parties have not intended the writing to be complete and final embodiment of their agreement and the parol evidence does not contradict the terms of the writing.