# Conditional Generation of Components

## Library elements

In the HRB it is often necessary to insert a library element only under certain conditions. As with point symbols, it is possible to prevent the creation of library elements by using a specific value. For this purpose, offsets are set to -999999.

Example: A formula is entered in the field for the offset, which could look as follows:

**`(Condition);(Formula for satisfied condition);(Formula for unsatisfied condition)`**

(Condition);(Offset for satisfied condition);(-999999)

The following offset is used for the different library elements:

* Partition library elements: *Offset*
* Wall end - \* - library element: *X offset*
* T-joints - \* - library element: *X offset*
* Openings - \* - lib. elem.: *X offset.* Library elements can be switched separately for left and right.

## Plates, profile members

Also for bars, profile members, or plates, a condition is sometimes used to determine whether the component is generated. Until now, the cross-section dimensions were set to 0.0 for this purpose. However, when identification numbers with profile members or plates with a predefined thickness (component catalog) are used, these cross-section dimensions are overwritten by values from the component catalog and cannot be set to 0.0. Therefore it is now possible to disable the component by setting the X offset or Y offset to -999999.

Example, see chapter: Library elements.
