| IPROB | problem option |
| 1 | elliptic boundary value problem |
| 2 | obstacle problem |
| 3 | continuation problem |
| 4 | parameter identification problem |
| 5 | optimal control problem |
| -1 | DD solve for elliptic boundary value problem |
| -2 | DD solve for obstacle problem |
| -3 | DD solve for continuation problem |
| -4 | DD solve for parameter identification problem |
| -5 | DD solve for optimal control problem |
| ITASK | IPROB | option |
| 0 | 1 | default |
| 0 | 2 | default |
| 0 | 3 | continue to the nearest target point |
| 1 | continue to the nearest target or singular point | |
| 2 | switch branches at a bifurcation point | |
| 3 | switch |
|
| 4 | switch |
|
| 5 | solve with |
|
| 6 | solve with |
|
| 7 | solve with |
|
| 0 | 4 | default |
| 8 | switch |
|
| 0 | 5 | default |
| ISPD | storage/iteration options |
| 0 | nonsymmetric/biconjugate gradient |
| 1 | symmetric/conjugate gradient |