  Complementarity and entanglement are fundamental features of Quantum
Mechanics that were recently related in triality equalities that involve
quantum coherence, the wave aspect of a qubit, and quantum predictability and
quantum entanglement, the particle aspect of a qubit. In this article, we give
an operational connection between redictability and entanglement in
entanglement swapping from initially partially entangled states. For this, we
show that the predictability of the pre-measurement one-qubit density matrix is
directly related to the probability of the partially entangled component of the
post-measurement state. Going even further, we analyze the entanglement
swapping for partially entangled states in the light of complementarity
relations and show that, in the cases where the entanglement increases after a
Bell-basis measurement, the predictability is consumed when compared to the
initially prepared state.
