LilyPond Internals Reference: 3.1.109 System

### 3.1.109 System

System objects are not created by any engraver.

Standard settings:

> `axes` (list):

>   `'(0 1)`

>   List of axis numbers. In the case of alignment grobs, this should contain only one number.

> `skyline-horizontal-padding` (number):

>   `0.5`

>   For determining the vertical distance between two staves, it is possible to have a configuration which would result in a tight interleaving of grobs from the top staff and the bottom staff. The larger this parameter is, the farther apart the staves are placed in such a configuration.

> `vertical-skylines` (pair of skylines):

>   `ly:axis-group-interface::calc-skylines`

>   Two skylines, one above and one below this grob.

> `X-extent` (pair of numbers):

>   `ly:axis-group-interface::width`

>   Hard coded extent in X direction.

> `Y-extent` (pair of numbers):

>   `ly:system::height`

>   Hard coded extent in Y direction.

This object supports the following interface(s): axis-group-interface, grob-interface, spanner-interface and system-interface.

#### Internals Reference