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.
For the specific 6120a discrete mathematics and i could not find information about it , can you provide more context about it, what topic it cover or what book it belong to . Propositional logic is a branch of logic that
A set $A$ is a subset of a set $B$, denoted by $A \subseteq B$, if every element of $A$ is also an element of $B$. denoted by $A \subseteq B$