Source paper: released examination archive, member 2020/T/a16608w1.pdf. The printed sitting is 27 May 2021; the ZIP directory names 2020. All three questions and all 21 marked subparts are answered. This is the canonical CS paper; the raster-identical Physics-held copy is a source reference, while Mathematics C7.4 is a different examination.[ref]
An identical copy is available in the released combined PDF, pages 111–115. Its historical folder and attachment name do not change the Computer Science cover identity.
Tensor factors follow their displayed subsystem order, and the rightmost operator acts first. Computational labels are ; Hadamard- and Pauli-Y-basis labels are the corresponding plus/minus eigenvalue labels. The exact correlations in Question 2 are interpreted as ideal probability-one predictions, not certainty inferred from a finite experimental sample.