hsc3-0.16: Help/UGen/sum3.help.lhs

    > Sound.SC3.UGen.Help.viewSC3Help "Sum3"
    > Sound.SC3.UGen.DB.ugenSummary "Sum3"

> import Sound.SC3 {- hsc3 -}
>
> g_01 = sum3 (sinOsc AR 440 0) (sinOsc AR 441 0) (sinOsc AR 442 0) * 0.1