EQGROUP label=equation…;
The EQGROUP statement applies a group label to the specified list of equations in the model program. Equation groups identify sets of related equations. The equation groups can be used by the ANALYZEDEP= option in a subsequent SOLVE statement to help specify and understand the role of groups of equations in a SOLVE step. If an equation appears in more than one EQGROUP statement, the label that is specified in the last EQGROUP statement is applied to that equation.