Definition:Labeled Tree for Propositional Logic/Ancestor WFF

Definition
Let $\left({T, \mathbf H, \Phi}\right)$ be a labeled tree for propositional logic. A WFF that is attached to an ancestor node of a node $t$ is called an ancestor wff of $t$.

So a hypothesis WFF''' is an ancestor of every node of $T$.

Also known as
An ancestor WFF of $t$ is also referred as just a ancestor of $t$.