元-am| 彐2arxl2asxj ≠ ≠S ≤(Σ|ani|1x;D)(∑|as;|l:D ≠P 丿≠S ≤Rr|xs|R3|xr 1-ar|12-as≤RrRs返回 | | | | | || | rr ss r s  − a  − a x x  (  | | | |) (  | | | |)  js sj j j r rj j a x a x | | | |  Rr xs Rs xr | | | | rr ss  − a  − a  Rr Rs =|  | |  |  js sj j j r rj j a x a x