*EQUATION

Optional parameters

INPUT: Set this parameter equal to the name of the alternate input file containing the data lines for this option. See Input Syntax Rules for the syntax of such file names. If this parameter is omitted, it is assumed that the data follow the keyword line.

Data lines to define an equation

First line

Number of terms, N, in the equation.

Second line

Node number or node set label, P, of first nodal variable, $u_{i}^{P}$ .
Degree of freedom, i, at above node for variable $u_{i}^{P}$ .
Value of $A_{1}$ .
Node number or node set label, Q, of second nodal variable, $u_{j}^{Q}$ .
Degree of freedom, j, at above node for variable $u_{j}^{Q}$ .
Value of $A_{2}$ .
Etc., up to four terms per line.

Repeat the second data line as often as necessary to define all of the terms of the equation. No more than four terms can be defined on a line. To define another constraint, repeat the entire set of data lines.