In Section 2.3, we gave an example. An SDIF file for this example is given in Figure 3.21. The problem is given the name DOC. The groups are referred to as GROUP1/2/3 and the variables are X1/2/3. The vector of bounds is called BN1 and the two types of nonlinear element are ELEMENT1/2. The elemental variables are assigned names beginning with U and the internal variables for the second nonlinear element start with V. The two group types are GTYPE1/2. Finally the nonlinear element in GROUP2 is given the name G2E1, while those in GROUP3 are G3E1/2.