v A+B*(C-D)+E/(C-D)N 逆波兰:ABCD-*+ECD-N^/+ 四元式:(1)(-CDT1) (2)(*BT1T2) (3)(+AT2T3) (4)(-CDT4) (5)(^T4NT5) (6)(/ET5T6) (7)(+T3T6T7逆波兰 : A B C D - * + E C D – N ^ / + 四元式 : (1) ( - C D T1 ) (2) ( * B T1 T2) (3) ( + A T2 T3) (4) ( - C D T4) (5) ( ^ T4 N T5) (6) ( / E T5 T6) (7) ( + T3 T6 T7) 例 : A + B * ( C - D ) + E / ( C - D ) ^N