SECTIONS 620-624

620.  The presumptions established by this article, and all other
presumptions declared by law to be conclusive, are conclusive
presumptions.

622.  The facts recited in a written instrument are conclusively
presumed to be true as between the parties thereto, or their
successors in interest; but this rule does not apply to the recital
of a consideration.

623.  Whenever a party has, by his own statement or conduct,
intentionally and deliberately led another to believe a particular
thing true and to act upon such belief, he is not, in any litigation
arising out of such statement or conduct, permitted to contradict it.

624.  A tenant is not permitted to deny the title of his landlord at
the time of the commencement of the relation.