For each station:

$(9)=|(1)-(2)|100$

$(10)=|(5)-(6)|100$

$(11)=(9)-(10),$ check $1$:value in $(11)5m$

$(12)={\displaystyle \underset{?}{\overset{?}{}}}(11)$

$(13)=K_{\text{b}\text{a}\text{c}\text{k}}+(3)-(4)$

$(14)=K_{\text{f}\text{o}\text{r}\text{e}}+(7)-(8),$ check $2$ : absolute value in $(13)$ and $(14)3mm$

$(15)=(3)-(7)$

$(16)=(4)-(8)$

$(17)=(15)-(16)+-100mm$ check $3$:$(17)=(13)-(14)$

$(18)=\frac{(15)+(16)+-100mm}{2}$

$(18)$ is the difference in elevation

between back sight and fore sight.

$v_{ij}=-\frac{f_{hi}}{{\displaystyle \underset{?}{\overset{?}{}}}D}{D}_{ij}{v}_{ij}=-\frac{f_h}{{\displaystyle \underset{?}{\overset{?}{}}}n}{n}_{ij},h=a-b,h=$Dtan$+i-1$

$D=100(-)co{s}^2,{}_{i,i+1}={}_{i-1,i}+-180+-$