---
name: "addbddvarfirst"
section: "3"
platform: "linux"
package: "alliance"
version: "5.1.1-3"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/addbddvarfirst"
---

# addbddvarfirst(3)

adds a new variable, before all others.

## NAME

addbddvarfirst - adds a new variable, before all others.

## SYNOPSYS

```
#include "bdd101.h"
bddnode ∗addbddvarfirst( BddSystem )
  bddsystem ∗BddSystem;
```

## PARAMETERS

- *BddSystem*

  The **bdd** system.

## DESCRIPTION

**addbddvarfirst** creates a new variable, with the number 0, in the **bdd** system *BddSystem*. If a null pointer is given, the default **bdd** system is used.\

## RETURN VALUE

**addbddvarfirst** returns a pointer to the **bdd** node of the new variable.

## ERRORS

**"no more variables, error !"**

There is no variable number left.

## EXAMPLE

```
#include "bdd101.h"
   bddsystem  ∗BddSystem;
   bddnode    ∗BddNode;
   BddSystem  = createbddsystem( 100, 1000, 100, 50000 );
   BddNode = addbddvarfirst( (bddsystem ∗)0 );
   destroybddsystem( (bddsystem ∗)0 );
```

## SEE ALSO

[**bdd**(1)](/bdd/1.md)