let G be Go-board; :: thesis: ( 1 < width G & 1 < len G implies LSeg (((G * ((len G),(width G))) + |[1,1]|),(((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) c= ((Int (cell (G,(len G),(width G)))) \/ (Int (cell (G,((len G) -' 1),(width G))))) \/ {((G * ((len G),(width G))) + |[0,1]|)} )
assume that
A1: 1 < width G and
A2: 1 < len G ; :: thesis: LSeg (((G * ((len G),(width G))) + |[1,1]|),(((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) c= ((Int (cell (G,(len G),(width G)))) \/ (Int (cell (G,((len G) -' 1),(width G))))) \/ {((G * ((len G),(width G))) + |[0,1]|)}
set q2 = G * ((len G),(width G));
set q3 = G * (((len G) -' 1),(width G));
set r = 1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1);
A3: ((len G) -' 1) + 1 = len G by A2, XREAL_1:235;
then A4: (len G) -' 1 >= 1 by A2, NAT_1:13;
A5: (len G) -' 1 < len G by A3, NAT_1:13;
then (G * (((len G) -' 1),(width G))) `1 < (G * ((len G),(width G))) `1 by A1, A4, GOBOARD5:3;
then A6: ((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1) > 0 by XREAL_1:50;
then 1 < ((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1 by XREAL_1:29, XREAL_1:129;
then A7: 1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1) < 1 by XREAL_1:212;
A8: (G * ((len G),(width G))) `2 = (G * (1,(width G))) `2 by A1, A2, GOBOARD5:1
.= (G * (((len G) -' 1),(width G))) `2 by A1, A4, A5, GOBOARD5:1 ;
A9: (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) + |[1,1]|)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|))) `2 = (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) + |[1,1]|)) `2) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `2) by Lm1
.= ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (((G * ((len G),(width G))) + |[1,1]|) `2)) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `2) by Lm3
.= ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (((G * ((len G),(width G))) + |[1,1]|) `2)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|) `2)) by Lm3
.= ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (((G * ((len G),(width G))) `2) + (|[1,1]| `2))) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|) `2)) by Lm1
.= ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (((G * ((len G),(width G))) `2) + (|[1,1]| `2))) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) `2) + (|[0,1]| `2))) by Lm1
.= ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (((G * ((len G),(width G))) `2) + 1)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) `2) + (|[0,1]| `2))) by EUCLID:52
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `2)) + ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * 1)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) `2) + 1)) by EUCLID:52
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `2)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) `2))) + ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) + (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)))
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `2)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((1 / 2) * (((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G)))) `2)))) + 1 by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `2)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((1 / 2) * (((G * ((len G),(width G))) `2) + ((G * ((len G),(width G))) `2))))) + 1 by A8, Lm1
.= ((G * ((len G),(width G))) `2) + (|[0,1]| `2) by EUCLID:52
.= ((G * ((len G),(width G))) + |[0,1]|) `2 by Lm1 ;
A10: (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((1 / 2) * ((G * ((len G),(width G))) `1))) - ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((1 / 2) * ((G * (((len G) -' 1),(width G))) `1)))) + (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) = (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)
.= 1 by A6, XCMPLX_1:106 ;
(((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) + |[1,1]|)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|))) `1 = (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) + |[1,1]|)) `1) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `1) by Lm1
.= ((((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (G * ((len G),(width G)))) + ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * |[1,1]|)) `1) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `1) by RLVECT_1:def 5
.= ((((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (G * ((len G),(width G)))) `1) + (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * |[1,1]|) `1)) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `1) by Lm1
.= ((((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (G * ((len G),(width G)))) `1) + ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (|[1,1]| `1))) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `1) by Lm3
.= ((((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * (G * ((len G),(width G)))) `1) + ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * 1)) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `1) by EUCLID:52
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `1)) + (1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)))) + (((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) `1) by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `1)) + (1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)))) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|) `1)) by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `1)) + (1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)))) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) `1) + (|[0,1]| `1))) by Lm1
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `1)) + (1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)))) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) `1) + 0)) by EUCLID:52
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `1)) + (1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)))) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((1 / 2) * (((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G)))) `1))) by Lm3
.= (((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) `1)) + (1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)))) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * ((1 / 2) * (((G * ((len G),(width G))) `1) + ((G * (((len G) -' 1),(width G))) `1)))) by Lm1
.= ((G * ((len G),(width G))) `1) + 0 by A10
.= ((G * ((len G),(width G))) `1) + (|[0,1]| `1) by EUCLID:52
.= ((G * ((len G),(width G))) + |[0,1]|) `1 by Lm1 ;
then ((1 - (1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1))) * ((G * ((len G),(width G))) + |[1,1]|)) + ((1 / (((1 / 2) * (((G * ((len G),(width G))) `1) - ((G * (((len G) -' 1),(width G))) `1))) + 1)) * (((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) = |[(((G * ((len G),(width G))) + |[0,1]|) `1),(((G * ((len G),(width G))) + |[0,1]|) `2)]| by A9, EUCLID:53
.= (G * ((len G),(width G))) + |[0,1]| by EUCLID:53 ;
then (G * ((len G),(width G))) + |[0,1]| in LSeg (((G * ((len G),(width G))) + |[1,1]|),(((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) by A6, A7;
then A11: LSeg (((G * ((len G),(width G))) + |[1,1]|),(((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) = (LSeg (((G * ((len G),(width G))) + |[1,1]|),((G * ((len G),(width G))) + |[0,1]|))) \/ (LSeg (((G * ((len G),(width G))) + |[0,1]|),(((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|))) by TOPREAL1:5;
set I1 = Int (cell (G,(len G),(width G)));
set I2 = Int (cell (G,((len G) -' 1),(width G)));
A12: ((Int (cell (G,(len G),(width G)))) \/ (Int (cell (G,((len G) -' 1),(width G))))) \/ {((G * ((len G),(width G))) + |[0,1]|)} = (Int (cell (G,(len G),(width G)))) \/ ((Int (cell (G,((len G) -' 1),(width G)))) \/ ({((G * ((len G),(width G))) + |[0,1]|)} \/ {((G * ((len G),(width G))) + |[0,1]|)})) by XBOOLE_1:4
.= (Int (cell (G,(len G),(width G)))) \/ (((Int (cell (G,((len G) -' 1),(width G)))) \/ {((G * ((len G),(width G))) + |[0,1]|)}) \/ {((G * ((len G),(width G))) + |[0,1]|)}) by XBOOLE_1:4
.= ((Int (cell (G,(len G),(width G)))) \/ {((G * ((len G),(width G))) + |[0,1]|)}) \/ ((Int (cell (G,((len G) -' 1),(width G)))) \/ {((G * ((len G),(width G))) + |[0,1]|)}) by XBOOLE_1:4 ;
A13: LSeg (((G * ((len G),(width G))) + |[1,1]|),((G * ((len G),(width G))) + |[0,1]|)) c= (Int (cell (G,(len G),(width G)))) \/ {((G * ((len G),(width G))) + |[0,1]|)} by Th63;
LSeg (((G * ((len G),(width G))) + |[0,1]|),(((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) c= (Int (cell (G,((len G) -' 1),(width G)))) \/ {((G * ((len G),(width G))) + |[0,1]|)} by A3, A4, A5, Th55;
hence LSeg (((G * ((len G),(width G))) + |[1,1]|),(((1 / 2) * ((G * ((len G),(width G))) + (G * (((len G) -' 1),(width G))))) + |[0,1]|)) c= ((Int (cell (G,(len G),(width G)))) \/ (Int (cell (G,((len G) -' 1),(width G))))) \/ {((G * ((len G),(width G))) + |[0,1]|)} by A11, A13, A12, XBOOLE_1:13; :: thesis: verum