Creates a dot product network with feedforward towers.

observation_spec A nested tensor spec containing the specs for global as well as per-arm observations.
global_layers Iterable of ints. Specifies the layers of the global tower.
arm_layers Iterable of ints. Specifies the layers of the arm tower. The last element of arm_layers has to be equal to that of global_layers.
activation_fn A keras activation, specifying the activation function used in all layers. Defaults to relu.

A dot product network that takes observations adhering observation_spec and outputs reward estimates for every action.

ValueError If the last arm layer does not match the last global layer.