  Several principled measures of contextuality have been proposed for general
systems of random variables (i.e. inconsistentlly connected systems). The first
of such measures was based on quasi-couplings using negative probabilities
(here denoted by CNT3, Dzhafarov & Kujala, 2016). Dzhafarov and Kujala (2019)
introduced a measure of contextuality, CNT2, that naturally generalizes to a
measure of non-contextuality. Dzhafarov and Kujala (2019) additionally
conjectured that in the class of cyclic systems these two measures are
proportional. Here we prove that that conjecture is correct. Recently,
Cervantes (2023) showed the proportionality of CNT2 and the Contextual Fraction
measure (CNTF) introduced by Abramsky, Barbosa, and Mansfeld (2017). The
present proof completes the description of the interrelations of all
contextuality measures as they pertain to cyclic systems.
