(Program {+(Assignment {+(Identifier)+} {+(Integer)+})+} (Assignment ( (Identifier) (Identifier)) ( {-(Integer)-} (Integer) {+(Integer)+})) {+(Assignment {+(Identifier)+} {+( {+(Integer)+} {+(Integer)+})+})+} {-(Assignment {-(Identifier)-} {-(Integer)-})-} {-(Assignment {-(Identifier)-} {-( {-(Integer)-} {-(Integer)-})-})-})