  We address the question as to whether an entangled state that satisfies local
realism will give a violation of the same, after entanglement swapping in a
suitable scenario. We consider such possibility as a kind of superadditivity in
nonclassicality. Importantly, it will indicate that checking for violation of
local realism, in the state obtained after entanglement swapping, can be a
method for detecting entanglement in the input state of the swapping procedure.
We investigate various entanglement swapping schemes, which involve mixed
initial states. The strength of violation of local realism by the state
obtained after entanglement swapping, is compared with the one for the input
states. We obtain a kind of superadditivity of violation of local realism for
Werner states, consequent upon entanglement swapping involving
Greenberger-Horne-Zeilinger state measurements. We also discuss whether
entanglement swapping of specific states may be used in quantum repeaters with
a substantially reduced need to perform the entanglement distillation step.
