let n be Element of NAT ; :: thesis: for x being Element of dyadic n holds
( ((axis x,n) - 1) / (2 |^ n) < x & x < ((axis x,n) + 1) / (2 |^ n) )
let x be Element of dyadic n; :: thesis: ( ((axis x,n) - 1) / (2 |^ n) < x & x < ((axis x,n) + 1) / (2 |^ n) )
A1:
x = (axis x,n) / (2 |^ n)
by Def7;
A2:
( (- 1) + (axis x,n) < 0 + (axis x,n) & 0 + (axis x,n) < 1 + (axis x,n) )
by XREAL_1:10;
0 < 2 |^ n
by NEWTON:102;
hence
( ((axis x,n) - 1) / (2 |^ n) < x & x < ((axis x,n) + 1) / (2 |^ n) )
by A1, A2, XREAL_1:76; :: thesis: verum