Conclusive presumptions (evidence)

The following are instances of conclusive presumptions:

(a) ESTOPPEL. Whenever a party has, by his own declaration, act, or omission, intentionally and deliberately led to another to believe a particular thing true, and to act upon such belief, he cannot, in any litigation arising out of such declaration, act or omission, be permitted to falsify it; and

(b) TENANCY. The tenant is not permitted to deny the title of his landlord at the time of commencement of the relation of landlord and tenant between them. (Section 2 of Rule 131 of the Rules of Court)