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