 In the present section the pattern of Bell’s 1964 paper will be followed: formulation of a framework, derivation of an inequality, demonstration of a discrepancy between certain quantum mechanical expectation values and this inequality. As already mentioned, Bell’s 1964 derivation assumed an experiment involving perfect anticorrelation of the results of aligned Stern-Gerlach experiments on a pair of entangled spin-\(\frac{1}{2}\) particles. Experimental tests, in which perfect anticorrelation (or correlation) may be approximated but cannot be assumed to hold exactly, require this assumption to be relaxed. Papers which took the steps from Bell’s 1964 demonstration to the one given here are Clauser, Horne, Shimony and Holt (1969), Bell (1971), Clauser and Horne (1974), Aspect (1983) and Mermin  (1986).[3]  Other strategies for deriving Bell-type theorems will be mentioned in  Section 6.