# Linear program

### From Glossary

An optimization problem in which the objective and constraints are linear. Forms include and . The standard form assumes has full row rank. Computer systems ensure this by having a logical variable augmented, so the form appears, for example, as (also allowing general bounds on the variables). The original variables are called structural. Note that each logical variable can be a slack, surplus, or artificial variable, depending on the form of the original constraint. This computer form also represents a range constraint with simple bounds on the logical variable. Some bounds can be infinite (i.e., absent), and a free variable (logical or structural) is when both of its bounds are infinite.