Bases: abjad.core.abjadcore._Abjad
Used to specify systems starting at even intervals running down every page.
Set interval to a positive number. Set systems_per_page to a positive number. Set skip_systems_on_first_page to a positive integer less than systems_per_page, defaulting to 1.
abjad> specification = SystemYOffsets(38, 5)
SystemYOffsets([0], 44, 88, 132, 176 | 0, 44, 88, 132, 176 | ...)
Pass instances of this class to other layout functions.