Someone could explain the use for

Hi, someone could explain the use for
Does it means that the symbol will have multiple outputs?
it’s parellarl output right ? rather than output one after another?

Hello @xysong1201,
mx.symbol.Group() enables parallel output thus a model with multiple heads.
One examplary usage is an AlphaZero-like model head:

You can also find a visualization of the corresponding NN architecture.

You can do the same in the Gluon-API like this:

    def hybrid_forward(self, F, x):
        out = self.body(x)
        value = self.value_head(out)
        policy = self.policy_head(out)
        return [value, policy]

and define a custom linear combination of the loss: