whereami display current instruction calling tree

## Syntax

    whereami()

## Description

Displays calling tree to instruction which contain `whereami()`. May be used within `pause` levels.

## Examples

    deff('y=test(a)',['y=sin(a)+1';
                      'y=t1(y)';
                      'y=y+1'])
    deff('y=t1(y)',['y=y^2';'whereami()'])
    test(1)

## See also

- where
- pause