Reasoning foundations
Constraint
A rule that restricts which values or states are allowed.
Definition
Constraint
A constraint is a condition that a proposed solution must satisfy.
Several constraints define a set of allowed solutions. A solver searches that set or proves that the set is empty.
01
Example
The rules x > 3 and x < 6 restrict an integer x to 4 or 5.
02
Important distinction
A preference such as 'smaller is better' is not a constraint until it receives an exact condition or objective.
After reading this article, you should be able to
- Define Constraint in the sense used on this site.
- Translate a short rule into a condition on allowed values.