let a, b, i, m be Nat; :: thesis: for D being non empty Subset of (TOP-REAL 2) st 2 <= m & m < len (Gauge (D,i)) & 1 <= a & a <= len (Gauge (D,i)) & 1 <= b & b <= len (Gauge (D,(i + 1))) holds
((Gauge (D,i)) * (m,a)) `1 = ((Gauge (D,(i + 1))) * (((2 * m) -' 2),b)) `1

let D be non empty Subset of (TOP-REAL 2); :: thesis: ( 2 <= m & m < len (Gauge (D,i)) & 1 <= a & a <= len (Gauge (D,i)) & 1 <= b & b <= len (Gauge (D,(i + 1))) implies ((Gauge (D,i)) * (m,a)) `1 = ((Gauge (D,(i + 1))) * (((2 * m) -' 2),b)) `1 )
set I = Gauge (D,i);
set J = Gauge (D,(i + 1));
set z = N-bound D;
set e = E-bound D;
set s = S-bound D;
set w = W-bound D;
assume that
A1: 2 <= m and
A2: m < len (Gauge (D,i)) and
A3: 1 <= a and
A4: a <= len (Gauge (D,i)) and
A5: 1 <= b and
A6: b <= len (Gauge (D,(i + 1))) ; :: thesis: ((Gauge (D,i)) * (m,a)) `1 = ((Gauge (D,(i + 1))) * (((2 * m) -' 2),b)) `1
m < (2 |^ i) + 3 by A2, JORDAN8:def 1;
then (2 * m) -' 2 <= (2 |^ (i + 1)) + 3 by Lm13;
then A7: (2 * m) -' 2 <= len (Gauge (D,(i + 1))) by JORDAN8:def 1;
A8: len (Gauge (D,(i + 1))) = width (Gauge (D,(i + 1))) by JORDAN8:def 1;
1 <= (2 * m) -' 2 by A1, Lm11;
then A9: [((2 * m) -' 2),b] in Indices (Gauge (D,(i + 1))) by A5, A6, A8, A7, MATRIX_0:30;
A10: len (Gauge (D,i)) = width (Gauge (D,i)) by JORDAN8:def 1;
1 <= m by A1, XXREAL_0:2;
then [m,a] in Indices (Gauge (D,i)) by A2, A3, A4, A10, MATRIX_0:30;
hence ((Gauge (D,i)) * (m,a)) `1 = |[((W-bound D) + ((((E-bound D) - (W-bound D)) / (2 |^ i)) * (m - 2))),((S-bound D) + ((((N-bound D) - (S-bound D)) / (2 |^ i)) * (a - 2)))]| `1 by JORDAN8:def 1
.= (W-bound D) + ((((E-bound D) - (W-bound D)) / (2 |^ i)) * (m - 2)) by EUCLID:52
.= (W-bound D) + ((((E-bound D) - (W-bound D)) / (2 |^ (i + 1))) * (((2 * m) -' 2) - 2)) by A1, Lm10
.= |[((W-bound D) + ((((E-bound D) - (W-bound D)) / (2 |^ (i + 1))) * (((2 * m) -' 2) - 2))),((S-bound D) + ((((N-bound D) - (S-bound D)) / (2 |^ (i + 1))) * (b - 2)))]| `1 by EUCLID:52
.= ((Gauge (D,(i + 1))) * (((2 * m) -' 2),b)) `1 by A9, JORDAN8:def 1 ;
:: thesis: verum