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. Access,

. Access, Path(X,Y) can be made 3-ary in the following way, Access(Y)

, Access(1,c,c)

, Given a Datalog program P, we can always modify P so that there is only one recursive rule and one "output" rule in P. The idea is to first convert P into a n-ary program P ? (for some n) then creates a unique n + 1 rules that takes as its first argument the name of the rule. For instance

, Rec(access,1,c,c)

. Rec,

, Output(X) :-Rec