Moreover, it follows--from P2, P6 and T4*--that every individual exemplifies every haecceity just in case some haecceity is such that every individual exemplifies it:
P2 for allxy(x = yequivalentfor somez(x ex Z & y ex Z))

P6 for allxy(x ex Yif-thenx ex X)

T4* for allxyz(x = yif-then(x ex Zequivalenty ex Z))

T20 for allxy(x ex Y)equivalentfor someyfor allx(x ex Y)