# SIGN_R

```{index} single: SIGN_R
```

this function return true if the real input is negative

## Interface

### Event Inputs

| Name | Comment | With |
| :--- | :--- | :--- |
| REQ | | in |

### Event Outputs

| Name | Comment | With |
| :--- | :--- | :--- |
| CNF | | |

### Input Vars

| Name | Type | Comment |
| :--- | :--- | :--- |
| in | REAL | |

### Output Vars

| Name | Type | Comment |
| :--- | :--- | :--- |
| | BOOL | |