Slack variable

2020 Mathematics Subject Classification: Primary: 90C05 [MSN][ZBL]

surplus variable

A non-negative variable $y_{i}$ that is introduced for a (linear) constraint $\sum_{j} a_{i j} x_{j} \leq b_{i}$ in a mathematical programming or linear programming problem to convert this inequality into an equality $y_{i} + \sum_{j} a_{i j} x_{j} = b_{i}$ . If this is done for all inequalities in a linear programming problem, one sometimes speaks of logical variables.