the other photon occur in region 2. He derives a condition analogous to (\[3\]) and uses it to prove a CHSH inequality whose violation is predicted by quantum mechanics for the chosen entangled state for certain sets of choices of $a,b$.[^2]$$Pr(A,B|a,b,c,\lambda )=Pr(A|a,c,\lambda ).Pr(B|b,c,\lambda ) 
\tag{Factorizability}  \label{Factorizability}$$Not only did this proof not assume the theory of local beables was deterministic, even this (Factorizability) condition was not assumed but derived from the reformulated local causality requirement.

Bell’s formulation of local causality (LC) has been carefully analyzed by Norsen \[2011\], whose analysis has been further improved by Seevinck and Uffink \[2011\]. They have focused in their analyses on what exactly is involved in a sufficient specification of what happens in the backward light cone of 1. This specification could fail to be sufficient through failing to mention local beables in 3 correlated with local beables in 2 through a joint correlation with local beables in the overlap of the backward light cones of 1 and 2. A violation of a local causality condition that did not require such a sufficient specification would pose no threat to the intuitive principle of local causality: specification of beables in 2 could alter the probabilities of beables 