2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/65045We define a closure operation for ideals in a commutative ring which has all the good properties of solid closure (at least in the case of equal characteristic) but such that also every ideal in a regular ring is closed. This gives in particular a kind of tight closure theory in characteristic zero without referring to positive characteristic.23 pagesCommutative Algebra13A35; 14H60; 14J26text