SWI-Prolog -- constraint/3

Documentation
- Reference manual
  - The SWI-Prolog library
    - library(simplex): Solve linear programming problems
      - Introduction
        
        gen_state/1
        
        constraint/3
        
        maximize/3
        
        minimize/3
        
        variable_value/3
        
        objective/2
- Packages

Availability::- use_module(library(simplex)).

constraint(+Constraint, +S0, -S)

Adds a linear or integrality constraint to the linear program corresponding to state S0. A linear constraint is of the form Left Op C, where Left is a list of Coefficient*Variable terms (variables in the context of linear programs can be atoms or compound terms) and C is a non-negative numeric constant. The list represents the sum of its elements. Op can be =, =< or >=. The coefficient 1 can be omitted. An integrality constraint is of the form integral(Variable) and constrains Variable to an integral value.