add new specialisation type intervals:non_empty_interval()
add new specialisation type intervals:non_empty_interval()
tectronics/scalaris,seyyed/scalaris,seyyed/scalaris,seyyed/scalaris,digshock/scalaris,seyyed/scalaris,digshock/scalaris,digshock/scalaris,digshock/scalaris,tectronics/scalaris,digshock/scalaris,tectronics/scalaris,seyyed/scalaris,tectronics/scalaris,tectronics/scalaris,tectronics/scalaris,seyyed/scalaris,digshock/scalaris,digshock/scalaris,seyyed/scalaris,tectronics/scalaris