let i be Element of NAT ; :: thesis: for G being Go-board st 1 < width G & 1 <= i & i + 1 < len G holds
LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),(((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|) c= ((Int (cell G,i,(width G))) \/ (Int (cell G,(i + 1),(width G)))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)}

let G be Go-board; :: thesis: ( 1 < width G & 1 <= i & i + 1 < len G implies LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),(((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|) c= ((Int (cell G,i,(width G))) \/ (Int (cell G,(i + 1),(width G)))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)} )
assume A1: ( 1 < width G & 1 <= i & i + 1 < len G ) ; :: thesis: LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),(((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|) c= ((Int (cell G,i,(width G))) \/ (Int (cell G,(i + 1),(width G)))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)}
set p1 = G * i,(width G);
set p2 = G * (i + 1),(width G);
set q3 = G * (i + 2),(width G);
set r = (((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ));
A2: i + 1 >= 1 by NAT_1:11;
i <= i + 1 by NAT_1:11;
then A3: i < len G by A1, XXREAL_0:2;
then A4: (G * i,(width G)) `2 = (G * 1,(width G)) `2 by A1, GOBOARD5:2
.= (G * (i + 1),(width G)) `2 by A1, A2, GOBOARD5:2 ;
A5: (i + 1) + 1 = i + (1 + 1) ;
then A6: i + (1 + 1) <= len G by A1, NAT_1:13;
A7: i + 2 >= 1 by A5, NAT_1:11;
A8: (G * (i + 1),(width G)) `2 = (G * 1,(width G)) `2 by A1, A2, GOBOARD5:2
.= (G * (i + 2),(width G)) `2 by A1, A6, A7, GOBOARD5:2 ;
i + 1 < i + 2 by XREAL_1:8;
then (G * (i + 1),(width G)) `1 < (G * (i + 2),(width G)) `1 by A1, A2, A6, GOBOARD5:4;
then A9: ((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 ) < ((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ) by XREAL_1:11;
i < i + 1 by XREAL_1:31;
then (G * i,(width G)) `1 < (G * (i + 1),(width G)) `1 by A1, GOBOARD5:4;
then A10: ((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 ) > 0 by XREAL_1:52;
then A11: 0 < (((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )) by A9, XREAL_1:141;
A12: (((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )) < 1 by A9, A10, XREAL_1:191;
((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )) = ((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 ) by A9, A10, XCMPLX_1:88;
then A13: (G * (i + 1),(width G)) `1 = ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((G * i,(width G)) `1 )) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((G * (i + 2),(width G)) `1 )) ;
A14: 1 * ((G * (i + 1),(width G)) `2 ) = ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((G * i,(width G)) `2 )) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((G * (i + 2),(width G)) `2 )) by A4, A8
.= (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) `2 ) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((G * (i + 2),(width G)) `2 )) by Lm3
.= (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) `2 ) + ((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))) `2 ) by Lm3
.= (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))) `2 by Lm1 ;
1 * ((G * (i + 1),(width G)) `1 ) = (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) `1 ) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((G * (i + 2),(width G)) `1 )) by A13, Lm3
.= (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) `1 ) + ((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))) `1 ) by Lm3
.= (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))) `1 by Lm1 ;
then A15: ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))) = |[((G * (i + 1),(width G)) `1 ),((G * (i + 1),(width G)) `2 )]| by A14, EUCLID:57
.= G * (i + 1),(width G) by EUCLID:57 ;
A16: now
G * (i + 1),(width G) = 1 * (G * (i + 1),(width G)) by EUCLID:33
.= ((1 / 2) * (G * (i + 1),(width G))) + ((1 / 2) * (G * (i + 1),(width G))) by Lm6, EUCLID:37
.= ((1 / 2) * (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) + ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G)))) + ((1 / 2) * (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))))) by A15, EUCLID:33
.= ((1 / 2) * (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))))) + ((1 / 2) * (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))))) by EUCLID:37
.= (((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))))) + ((1 / 2) * (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))))) by EUCLID:36
.= (((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))))) + (((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))))) by EUCLID:36
.= ((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G)))) + (((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G)))) + (((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))))) by EUCLID:30
.= ((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G)))) + (((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G)))) + (((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))))) by EUCLID:30
.= (((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G)))) + ((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))))) + (((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))))) by EUCLID:30
.= ((((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G)))) + ((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))) by EUCLID:30
.= (((1 / 2) * (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * (i + 1),(width G))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (G * i,(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))) by EUCLID:36
.= (((1 / 2) * ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((G * i,(width G)) + (G * (i + 1),(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))) by EUCLID:36
.= ((((1 / 2) * (1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))))) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G)))) by EUCLID:34 ;
hence G * (i + 1),(width G) = (((1 / 2) * (1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))))) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + (((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))))) by EUCLID:30
.= (((1 / 2) * (1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))))) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + ((1 / 2) * ((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 1),(width G))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (G * (i + 2),(width G))))) by EUCLID:36
.= (((1 / 2) * (1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))))) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) by EUCLID:36
.= ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G))))) + ((1 / 2) * (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) by EUCLID:34
.= ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G))))) + (((1 / 2) * ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) by EUCLID:34
.= ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G))))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) by EUCLID:34 ;
:: thesis: verum
end;
((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|)) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|)) = (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G))))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * |[0 ,1]|)) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * (((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|)) by EUCLID:36
.= (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G))))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * |[0 ,1]|)) + ((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * |[0 ,1]|)) by EUCLID:36
.= ((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) + (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G))))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * |[0 ,1]|))) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * |[0 ,1]|) by EUCLID:30
.= (((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * |[0 ,1]|)) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * |[0 ,1]|) by EUCLID:30
.= ((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))))) + (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * |[0 ,1]|) + (((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * |[0 ,1]|)) by EUCLID:30
.= ((((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 ))) * ((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G))))) + ((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * ((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))))) + (((1 - ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) + ((((G * (i + 1),(width G)) `1 ) - ((G * i,(width G)) `1 )) / (((G * (i + 2),(width G)) `1 ) - ((G * i,(width G)) `1 )))) * |[0 ,1]|) by EUCLID:37
.= (G * (i + 1),(width G)) + |[0 ,1]| by A16, EUCLID:33 ;
then (G * (i + 1),(width G)) + |[0 ,1]| in LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),(((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|) by A11, A12;
then A17: LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),(((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|) = (LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),((G * (i + 1),(width G)) + |[0 ,1]|)) \/ (LSeg ((G * (i + 1),(width G)) + |[0 ,1]|),(((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|)) by A11, A12, TOPREAL1:11;
set I1 = Int (cell G,i,(width G));
set I2 = Int (cell G,(i + 1),(width G));
A18: LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),((G * (i + 1),(width G)) + |[0 ,1]|) c= (Int (cell G,i,(width G))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)} by A1, A3, Th58;
A19: LSeg (((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|),((G * (i + 1),(width G)) + |[0 ,1]|) c= (Int (cell G,(i + 1),(width G))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)} by A1, A5, Th57, NAT_1:11;
((Int (cell G,i,(width G))) \/ (Int (cell G,(i + 1),(width G)))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)} = (Int (cell G,i,(width G))) \/ ((Int (cell G,(i + 1),(width G))) \/ ({((G * (i + 1),(width G)) + |[0 ,1]|)} \/ {((G * (i + 1),(width G)) + |[0 ,1]|)})) by XBOOLE_1:4
.= (Int (cell G,i,(width G))) \/ (((Int (cell G,(i + 1),(width G))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)}) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)}) by XBOOLE_1:4
.= ((Int (cell G,i,(width G))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)}) \/ ((Int (cell G,(i + 1),(width G))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)}) by XBOOLE_1:4 ;
hence LSeg (((1 / 2) * ((G * i,(width G)) + (G * (i + 1),(width G)))) + |[0 ,1]|),(((1 / 2) * ((G * (i + 1),(width G)) + (G * (i + 2),(width G)))) + |[0 ,1]|) c= ((Int (cell G,i,(width G))) \/ (Int (cell G,(i + 1),(width G)))) \/ {((G * (i + 1),(width G)) + |[0 ,1]|)} by A17, A18, A19, XBOOLE_1:13; :: thesis: verum