> Sound.SC3.UGen.Help.viewSC3Help "FOS"
> Sound.SC3.UGen.DB.ugenSummary "FOS"

> import Sound.SC3.ID

Same as OnePole.
> let x = lfTri AR 0.4 0 * 0.99
> in audition (out 0 (fos (lfSaw AR 200 0 * 0.2) (1 - (abs x)) 0 x))

Same as OneZero
> let x = lfTri AR 0.4 0 * 0.99
> in audition (out 0 (fos (lfSaw AR 200 0 * 0.2) (1 - (abs x)) x 0))