> :t mrg2

> import Sound.SC3

mrg2 defines a node indicating a multiple root graph.
> let {l = out 0 (sinOsc AR 300 0 * 0.1)
>     ;r = out 1 (sinOsc AR 900 0 * 0.1)}
> in audition (mrg2 l r)

there is a leftmost rule, so that mrg nodes need not
be terminal.
> let {l = sinOsc AR 300 0 * 0.1
>     ;r = out 1 (sinOsc AR 900 0 * 0.1)}
> in audition (out 0 (mrg2 l r))

the leftmost node may be an mce node
> let {l = sinOsc AR (mce2 300 400) 0 * 0.1
>     ;r = out 1 (sinOsc AR 900 0 * 0.1)}
> in audition (out 0 (mrg2 l r))

the implementation is not thorough
> let {l = sinOsc AR (mce2 300 400) 0 * 0.1
>     ;r = out 1 (sinOsc AR 900 0 * 0.1)}
> in audition (out 0 (mrg2 l r + mrg2 l r))