let i, j be Element of NAT ; for D being non empty Subset of (TOP-REAL 2) st i <= j holds
len (Gauge D,i) <= len (Gauge D,j)
let D be non empty Subset of (TOP-REAL 2); ( i <= j implies len (Gauge D,i) <= len (Gauge D,j) )
assume
i <= j
; len (Gauge D,i) <= len (Gauge D,j)
then A1:
2 |^ i <= 2 |^ j
by PREPOWER:107;
( len (Gauge D,i) = (2 |^ i) + 3 & len (Gauge D,j) = (2 |^ j) + 3 )
by JORDAN8:def 1;
hence
len (Gauge D,i) <= len (Gauge D,j)
by A1, XREAL_1:8; verum