let d be Dyadic; ( 0 <= d & d is not Integer implies ex n, m, p being Nat st
( d = n + (((2 * m) + 1) / (2 |^ (p + 1))) & (2 * m) + 1 < 2 |^ (p + 1) ) )
assume A1:
( 0 <= d & d is not Integer )
; ex n, m, p being Nat st
( d = n + (((2 * m) + 1) / (2 |^ (p + 1))) & (2 * m) + 1 < 2 |^ (p + 1) )
then consider p being Nat, i being Integer such that
A2:
d = ((2 * i) + 1) / (2 |^ (p + 1))
by Th23;
i >= 0
then reconsider i = i as Element of NAT by INT_1:3;
set DV = ((2 * i) + 1) div (2 |^ (p + 1));
set MD = ((2 * i) + 1) mod (2 |^ (p + 1));
A3:
2 |^ (p + 1) = 2 * (2 |^ p)
by NEWTON:6;
A4:
(2 * i) + 1 = ((((2 * i) + 1) div (2 |^ (p + 1))) * (2 |^ (p + 1))) + (((2 * i) + 1) mod (2 |^ (p + 1)))
by INT_1:59;
then
(2 * i) + 1 >= ((((2 * i) + 1) div (2 |^ (p + 1))) * (2 |^ p)) * 2
by A3, NAT_1:11;
then
(2 * i) + 1 > ((((2 * i) + 1) div (2 |^ (p + 1))) * (2 |^ p)) * 2
by XXREAL_0:1;
then
i >= (((2 * i) + 1) div (2 |^ (p + 1))) * (2 |^ p)
by XREAL_1:68, NAT_1:13;
then reconsider M = i - ((((2 * i) + 1) div (2 |^ (p + 1))) * (2 |^ p)) as Nat by NAT_1:21;
take
((2 * i) + 1) div (2 |^ (p + 1))
; ex m, p being Nat st
( d = (((2 * i) + 1) div (2 |^ (p + 1))) + (((2 * m) + 1) / (2 |^ (p + 1))) & (2 * m) + 1 < 2 |^ (p + 1) )
take
M
; ex p being Nat st
( d = (((2 * i) + 1) div (2 |^ (p + 1))) + (((2 * M) + 1) / (2 |^ (p + 1))) & (2 * M) + 1 < 2 |^ (p + 1) )
take
p
; ( d = (((2 * i) + 1) div (2 |^ (p + 1))) + (((2 * M) + 1) / (2 |^ (p + 1))) & (2 * M) + 1 < 2 |^ (p + 1) )
A5: ((2 * i) + 1) mod (2 |^ (p + 1)) =
((2 * i) + 1) - ((((2 * i) + 1) div (2 |^ (p + 1))) * (2 |^ (p + 1)))
by A4
.=
(2 * M) + 1
by A3
;
thus d =
(((((2 * i) + 1) div (2 |^ (p + 1))) * (2 |^ (p + 1))) + (((2 * i) + 1) mod (2 |^ (p + 1)))) / (2 |^ (p + 1))
by INT_1:59, A2
.=
(((2 * i) + 1) div (2 |^ (p + 1))) + (((2 * M) + 1) / (2 |^ (p + 1)))
by A5, XCMPLX_1:113
; (2 * M) + 1 < 2 |^ (p + 1)
thus
(2 * M) + 1 < 2 |^ (p + 1)
by A5, INT_1:58; verum