'Apply the backward pass transformation to the input data.
Arguments:
error (Tensor): deltas back propagated from the adjacent higher layer
Returns:
Tensor: deltas to propagate to the adjacent lower layer'

def bprop(self, error, alpha=1.0, beta=0.0):

    for (l, e, a, b) in reversed(list(zip(self.layers, error, self.alphas, self.betas))):
        l.bprop(e, alpha=a, beta=b)
