SLP variables

A variable which appears in a nonlinear coefficient or term is described as an SLP variable.

Normally, any variable which has a nonlinear coefficient will also be treated as an SLP variable. However, it is possible to set options so that variables which do not appear in nonlinear coefficients or terms are not treated as SLP variables.

Any variable, whether it is related to a nonlinear term or not, can be defined by the user as an SLP variable. This is most easily achieved by setting an initial value for the variable.