  We propose here a setup to generate and evaluate the entanglement between two
mechanical resonators in a cavity optomechanical setting. As in previous
proposals, our scheme includes two driving pumps allowing for the generation of
two-mode mechanical squeezing. In addition, we include here four additional
probing tones, which allow for the separate evaluation of the collective
mechanical quadratures required to estimate the Duan quantity, thus allowing us
to infer whether the mechanical resonators are entangled.
