All variables in the problem have at least one legal value within their bounds that does not violate any constraints when considered with the lowest and highest possible values of all other variables.

Ensures that no two variables within a set can have the same value at their boundaries.

Ensures that every variable within a set meets minimum and maximum value constraints individually.

A variable must either maximize or minimize its value within the constraints set by adjacent variables in the problem.

Variables are assigned values sequentially from the lowest possible value to the highest, ensuring that all constraints are met before moving to the next variable.