[Chimera-users] how2 select named selections using command-line [chimera1.5.3]

dear chimera users, i can defined named selections and they work under the select menu. however, i canNOT use the command line to select them; e.g., i have 4 named selections 0a,0b,1a,1b dis 0a | 1a works sel 1a NOT working sel :1a NOT working (said selection cleared) i like to be able to select multiple named selections and further apply filters on them; e.g., "select 1a and 1b and atoms=side chain atoms" how do i accomplish this? as always thank you very much. fred