  The violation of a Bell inequality certifies the presence of entanglement
even if neither party trusts their measurement devices. Recently Moroder et.
al. showed how to make this statement quantitative, using semidefinite
programming to calculate how much entanglement is certified by a given
violation. Here I adapt their techniques to the case where Bob's measurement
devices are in fact trusted, the setting for "EPR-steering" inequalities.
Interestingly, all of the steering inequalities studied turn out to require
negativity for their violation. This supports a significant strengthening of
Peres' conjecture that negativity is required to violate a bipartite Bell
inequality.
