Functions

The procedures TheFunction and IntervalFunction should be user written. They return the value of the equations (either as a vector of REAL or as a vector of INTERVAL, see 2.3.4.3) for given values or intervals for the unknowns. They take one argument which is the vector of REAL which describe the unknowns.

In the same way the procedures Gradient and IntervalGradient should be user written. They return the Jacobian matrix of the system of equations of the equations (either as a matrix of REAL or as a matrix of INTERVAL) for given values of the unknowns. The Gradient procedure take one argument which is the vector of REAL which describe the unknowns. The IntervalGradient procedure has three arguments and is described in section 2.4.2.2.