Constraints

Constraints represent logical restrictions on the values that decision variables can simultaneously take and that must be satisfied. There are various types of constraints that can be stated within Xpress Kalis:

• Linear constraint (equation, inequality, disequality), e.g.: x ≠ y, x = y, x ≤ y etc.
• Non-linear constraint (equation, inequality), e.g.: x = y / z, x * y + 2 * ln(z) = exp(w), x^2 + y^2 ≤ z^2 etc.
• Symbolic constraint, e.g.: all-different(x,y,z) meaning (x ≠ y) ∧ (x ≠ z) ∧ (x ≠ z)
• Logical relation, e.g.: x ≠ y ⇒ z = 3
• User-defined constraints such as generic_binary_constraint(x,y)

All constraints are represented by the type cpctr.