 This is the aforementioned assumption of measurement independence. It is also sometimes referred to as “no superdeterminism” because it is incompatible with a particularly strong form of determinism (“superdeterminism”) according to which the joint past of the measurement setting \(\alpha\) and the measured system state \(\lambda\) determines them both completely and induces a correlation between them. But, as pointed out in the first instance by Costa de Beauregard (1977a) and then by Price (1994, 1996), superdeterminism is not the only way in which Eq. (\ref{eq:independence}) can be violated: if there is retrocausality (understood along interventionist lines as outlined in  §2.1),  the choice of measurement setting \(\alpha\) may causally influence the physical state \(\lambda\) at an earlier time and thereby also render Eq. (\ref{eq:independence}) incorrect. Consequently, by postulating Eq. (\ref{eq:independence}) one assumes retrocausality to be absent.