Boolean logic
Literal
A Boolean variable or its negation.
Definition
Literal
A literal is either a Boolean variable, such as a, or a negated variable, such as not a.
Clauses are disjunctions of literals. SAT solvers use literals as the smallest assignments recorded in clauses and implication trails.
01
Example
a, not b, and c are the three literals in the clause a or not b or c.
02
Important distinction
The formula a and b is not one literal because it combines two variables.
After reading this article, you should be able to
- Define Literal in the sense used on this site.
- List the literals in a clause and state when each is true.