Locus

A locus ξ is a finite sequence of natural numbers. Loci are the ludic analogues of "formulas". Appending a bias (natural number) i corresponds to taking an immediate subformula: ξ*i is an immediate sublocus of ξ. There are as many subloci of ξ as there are natural numbers.

Girard translates "Locus Solum" as: Only the location matters.