The symmetric frame of a sup-lattice L is the frame freely generated by L with sups being preserved in the presentation. Classically (ie, with the truth value object being 2) it is easy to show that the injection of generators is 1-1. Does anyone know whether this also holds in an arbitrary topos? Thanks, ---------------------------------------------------------------------- Pedro Resende Departamento de Matemática Tel.: +351 218 417 149 Instituto Superior Técnico Fax: +351 218 417 048 / 598 Av. Rovisco Pais E-mail: pmr@math.ist.utl.pt 1049-001 Lisboa, Portugal WWW: http://www.math.ist.utl.pt/~pmr ----------------------------------------------------------------------