let G be Go-board; :: thesis: ( 1 < len G & 1 < width G implies LSeg (((G * (1,(width G))) + |[(- 1),1]|),(((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) c= ((Int (cell (G,0,(width G)))) \/ (Int (cell (G,0,((width G) -' 1))))) \/ {((G * (1,(width G))) - |[1,0]|)} )
assume that
A1: 1 < len G and
A2: 1 < width G ; :: thesis: LSeg (((G * (1,(width G))) + |[(- 1),1]|),(((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) c= ((Int (cell (G,0,(width G)))) \/ (Int (cell (G,0,((width G) -' 1))))) \/ {((G * (1,(width G))) - |[1,0]|)}
set q2 = G * (1,(width G));
set q3 = G * (1,((width G) -' 1));
set r = 1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1);
A3: ((width G) -' 1) + 1 = width G by A2, XREAL_1:235;
then A4: (width G) -' 1 >= 1 by A2, NAT_1:13;
A5: (width G) -' 1 < width G by A3, NAT_1:13;
then (G * (1,((width G) -' 1))) `2 < (G * (1,(width G))) `2 by A1, A4, GOBOARD5:4;
then A6: ((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2) > 0 by XREAL_1:50;
then 1 < ((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1 by XREAL_1:29, XREAL_1:129;
then A7: 1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1) < 1 by XREAL_1:212;
A8: (G * (1,(width G))) `1 = (G * (1,1)) `1 by A1, A2, GOBOARD5:2
.= (G * (1,((width G) -' 1))) `1 by A1, A4, A5, GOBOARD5:2 ;
A9: (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) + |[(- 1),1]|)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|))) `1 = (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) + |[(- 1),1]|)) `1) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `1) by Lm1
.= ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (((G * (1,(width G))) + |[(- 1),1]|) `1)) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `1) by Lm3
.= ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (((G * (1,(width G))) + |[(- 1),1]|) `1)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|) `1)) by Lm3
.= ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (((G * (1,(width G))) `1) + (|[(- 1),1]| `1))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|) `1)) by Lm1
.= ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (((G * (1,(width G))) `1) + (|[(- 1),1]| `1))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) `1) - (|[1,0]| `1))) by Lm2
.= ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (((G * (1,(width G))) `1) + (- 1))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) `1) - (|[1,0]| `1))) by EUCLID:52
.= ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (((G * (1,(width G))) `1) - 1)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) `1) - 1)) by EUCLID:52
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `1)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) `1))) - 1
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `1)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((1 / 2) * (((G * (1,(width G))) + (G * (1,((width G) -' 1)))) `1)))) - 1 by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `1)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((1 / 2) * (((G * (1,(width G))) `1) + ((G * (1,(width G))) `1))))) - 1 by A8, Lm1
.= ((G * (1,(width G))) `1) - (|[1,0]| `1) by EUCLID:52
.= ((G * (1,(width G))) - |[1,0]|) `1 by Lm2 ;
A10: (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((1 / 2) * ((G * (1,(width G))) `2))) - ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((1 / 2) * ((G * (1,((width G) -' 1))) `2)))) + (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) = (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)
.= 1 by A6, XCMPLX_1:106 ;
(((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) + |[(- 1),1]|)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|))) `2 = (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) + |[(- 1),1]|)) `2) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `2) by Lm1
.= ((((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (G * (1,(width G)))) + ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * |[(- 1),1]|)) `2) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `2) by RLVECT_1:def 5
.= ((((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (G * (1,(width G)))) `2) + (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * |[(- 1),1]|) `2)) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `2) by Lm1
.= ((((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (G * (1,(width G)))) `2) + ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (|[(- 1),1]| `2))) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `2) by Lm3
.= ((((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * (G * (1,(width G)))) `2) + ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * 1)) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `2) by EUCLID:52
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `2)) + ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * 1)) + (((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) `2) by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `2)) + (1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|) `2)) by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `2)) + (1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) `2) - (|[1,0]| `2))) by Lm2
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `2)) + (1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) `2) - 0)) by EUCLID:52
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `2)) + (1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((1 / 2) * (((G * (1,(width G))) + (G * (1,((width G) -' 1)))) `2))) by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) `2)) + (1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)))) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * ((1 / 2) * (((G * (1,(width G))) `2) + ((G * (1,((width G) -' 1))) `2)))) by Lm1
.= ((G * (1,(width G))) `2) - 0 by A10
.= ((G * (1,(width G))) `2) - (|[1,0]| `2) by EUCLID:52
.= ((G * (1,(width G))) - |[1,0]|) `2 by Lm2 ;
then ((1 - (1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1))) * ((G * (1,(width G))) + |[(- 1),1]|)) + ((1 / (((1 / 2) * (((G * (1,(width G))) `2) - ((G * (1,((width G) -' 1))) `2))) + 1)) * (((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) = |[(((G * (1,(width G))) - |[1,0]|) `1),(((G * (1,(width G))) - |[1,0]|) `2)]| by A9, EUCLID:53
.= (G * (1,(width G))) - |[1,0]| by EUCLID:53 ;
then (G * (1,(width G))) - |[1,0]| in LSeg (((G * (1,(width G))) + |[(- 1),1]|),(((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) by A6, A7;
then A11: LSeg (((G * (1,(width G))) + |[(- 1),1]|),(((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) = (LSeg (((G * (1,(width G))) + |[(- 1),1]|),((G * (1,(width G))) - |[1,0]|))) \/ (LSeg (((G * (1,(width G))) - |[1,0]|),(((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|))) by TOPREAL1:5;
set I1 = Int (cell (G,0,(width G)));
set I2 = Int (cell (G,0,((width G) -' 1)));
A12: ((Int (cell (G,0,(width G)))) \/ (Int (cell (G,0,((width G) -' 1))))) \/ {((G * (1,(width G))) - |[1,0]|)} = (Int (cell (G,0,(width G)))) \/ ((Int (cell (G,0,((width G) -' 1)))) \/ ({((G * (1,(width G))) - |[1,0]|)} \/ {((G * (1,(width G))) - |[1,0]|)})) by XBOOLE_1:4
.= (Int (cell (G,0,(width G)))) \/ (((Int (cell (G,0,((width G) -' 1)))) \/ {((G * (1,(width G))) - |[1,0]|)}) \/ {((G * (1,(width G))) - |[1,0]|)}) by XBOOLE_1:4
.= ((Int (cell (G,0,(width G)))) \/ {((G * (1,(width G))) - |[1,0]|)}) \/ ((Int (cell (G,0,((width G) -' 1)))) \/ {((G * (1,(width G))) - |[1,0]|)}) by XBOOLE_1:4 ;
A13: LSeg (((G * (1,(width G))) + |[(- 1),1]|),((G * (1,(width G))) - |[1,0]|)) c= (Int (cell (G,0,(width G)))) \/ {((G * (1,(width G))) - |[1,0]|)} by Th58;
LSeg (((G * (1,(width G))) - |[1,0]|),(((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) c= (Int (cell (G,0,((width G) -' 1)))) \/ {((G * (1,(width G))) - |[1,0]|)} by A3, A4, A5, Th49;
hence LSeg (((G * (1,(width G))) + |[(- 1),1]|),(((1 / 2) * ((G * (1,(width G))) + (G * (1,((width G) -' 1))))) - |[1,0]|)) c= ((Int (cell (G,0,(width G)))) \/ (Int (cell (G,0,((width G) -' 1))))) \/ {((G * (1,(width G))) - |[1,0]|)} by A11, A13, A12, XBOOLE_1:13; :: thesis: verum