... con-straint? In projection constraints, a value for the x variable has only onepossible extension to a value for the y variable; but a value for the y variablemay leave many possible values ... exam-ple, the family of all subsets containing at least 3 out of 4 fixed elements is2-intersecting, and is maximal for a certain range of values of k/n.Frankl [Fra78] investigated the full range ... Namely, for every x-value there is only one possibley-value that together would satisfy the constraint. An enhanced version of the PCP theorem states:Theorem 1.5 (The PCP Theorem [AS98], [ALM+98],...