Propositional logic is a branch of logic that deals with statements that can be either true or false. Propositional logic is used extensively in computer science, as it provides a formal framework for reasoning about Boolean expressions and logical statements.

Graph theory is a branch of discrete mathematics that deals with graphs, which are collections of nodes and edges.

A set is a collection of objects, denoted by $S = {a_1, a_2, ..., a_n}$, where $a_i$ are the elements of $S$.

A proposition is a statement that can be either true or false.

However based on general Discrete Mathematics concepts here some possible fixes:

add compare , contrast and reflective statements.

Proof techniques are used to establish the validity of mathematical statements. In computer science, proof techniques are used to verify the correctness of algorithms, data structures, and software systems.