下面证明,径迹长度估计是无偏的。 r%or(S =4exn+12,E Wn.(52-S)d exp Edl m2 n7 W,. '(s-S )dexptr'z,(m+/- 2, Em)di W.(S2-S,)expL E, (rm+1.92m,Em)dl W (s-S,)exp"E, ('mn+1-2, En +w, expL 2, (n+1.2,, En)dl ds W.explE, (r,+l92,, En)dl ds下面证明，径迹长度估计是无偏的。                                =  −  +   +  −  +   −  − −  +  =  − −  +  −  − −  +  = −  − −  +  = − −  +  =  −  +     +  2 1 2 1 2 2 2 1 2 0 0 0 2 1 0 2 1 0 1 0 2 1 0 0 0 * 0 0 0 1 * 0 0 * exp ( , ) exp ( , ) ( ) exp ( , ) ( ) exp ( , ) ( ) exp ( , ) ( ) exp ( , ) ( ) exp ( , ) ( ) ( ) ( ) ( , ) exp ( , ) s s s n t n n n s s s n t n n n s n t m m m s n t m m m s s s n t m m m s s n t m m m s n t m m m s n n t n n t m m m W l E dl ds W l E dl ds W s s l E dl W s s l E dl W s s d l E dl W s s d l E dl V d l E dl V f s ds V E l E dl ds r Ω r Ω r Ω r Ω r Ω r Ω r Ω r r Ω   