loss about l_unl is not clear

[SchafferZhang]

The loss with regard to the unlabeled data l_unl is defined as:
loss_unl = -0.5*T.mean(l_unl) + 0.5*T.mean(T.nnet.softplus(l_unl)) + 0.5*T.mean(T.nnet.softplus(l_gen))
But the first term contradicts with the second term, which obsess me a lot.