13C99 2 16D80 2 16U80 2 symmetric ring 2 $J$-symmetric ring 1 16S38; Secondary 14A22 1 16T20 1 2-primal rings 1 Jacobson radical 1 Primary 16S36 1 central Armendariz rings 1 central reduced rings 1 central reversible rings 1 central semicommutative rings 1 central symmetric rings 1 noncommutative ring 1 skew PBW extension 1 symmetric rings 1