# TaoALMMGetDualIS
Retrieve a pointer to the index set that identifies equality and inequality constraint components of the dual vector returned by `TaoALMMGetMultipliers()`. Not valid for problems with only one type of constraint. 
## Synopsis
```
#include "petsctao.h" 
#include "petscvec.h" 
PetscErrorCode TaoALMMGetDualIS(Tao tao, IS *eq_is, IS *ineq_is)
```

## Input Parameter

- ***tao -*** the Tao context for the `TAOALMM` solver



## Output Parameters

- ***eq_is -*** index set associated with the equality constraints (NULL if not needed)
- ***ineq_is -*** index set associated with the inequality constraints (NULL if not needed)





## See Also
 `TAOALMM`, `Tao`, `TaoALMMGetMultipliers()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/constrained/impls/almm/almmutils.c.html#TaoALMMGetDualIS">src/tao/constrained/impls/almm/almmutils.c</A>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/tao/constrained/impls/almm/almmutils.c)


[Index of all Tao routines](index.md)  
[Table of Contents for all manual pages](/docs/manualpages/index.md)  
[Index of all manual pages](/docs/manualpages/singleindex.md)  
