([dagger]) The contravariant tensor [g.sup.[alpha][beta]], determined by the main property [g.sub.[alpha][sigma]][g.sup.[sigma][beta]] = [[delta].sup.[beta].sub.[alpha]] of the fundamental metric tensor as ([g.sup.(0).sub.[alpha][sigma]] + [[zeta].sub.[alpha][sigma]]) [g.sup.[sigma][beta]] = [[delta].sup.[beta].sub.[alpha]], is [g.sup.[alpha][beta]] = [g.sup.(0)[alpha][beta]] - [[zeta].sup.[alpha][beta]], while its determinant is g = [g.sup.(0)(1 + [zeta]).