Definition:Substitution (Formal Systems)/Well-Formed Part/Example

Example
Let the WFFs of propositional logic $\mathbf A, \mathbf A'$ and $\mathbf B$ be as follows:

Then the substitution of $\mathbf A'$ for $\mathbf A$ in $\mathbf B$ is given by:


 * $\mathbf B \left({\mathbf A \,//\, \mathbf A'}\right) = \left({\neg p \lor q}\right) \iff \left({\neg q \implies \neg p}\right)$