let m, k be Nat; :: thesis: ( m >= 1 & k >= 2 implies for r being Tuple of (m + 2),(k -SD ) holds SDDec (Mmax r) >= SDDec r )
assume A1:
( m >= 1 & k >= 2 )
; :: thesis: for r being Tuple of (m + 2),(k -SD ) holds SDDec (Mmax r) >= SDDec r
A2:
m + 2 >= 1
by NAT_1:12;
let r be Tuple of (m + 2),(k -SD ); :: thesis: SDDec (Mmax r) >= SDDec r
for i being Nat st i in Seg (m + 2) holds
DigA (Mmax r),i >= DigA r,i
proof
let i be
Nat;
:: thesis: ( i in Seg (m + 2) implies DigA (Mmax r),i >= DigA r,i )
assume A3:
i in Seg (m + 2)
;
:: thesis: DigA (Mmax r),i >= DigA r,i
then A4:
DigA (Mmax r),
i = MmaxDigit r,
i
by Def4;
now per cases
( i >= m or i < m )
;
suppose
i < m
;
:: thesis: DigA (Mmax r),i >= DigA r,ithen A5:
DigA (Mmax r),
i = (Radix k) - 1
by A1, A3, A4, Def3;
A6:
DigA r,
i = r . i
by A3, RADIX_1:def 3;
r . i is
Element of
k -SD
by A3, RADIX_1:18;
hence
DigA (Mmax r),
i >= DigA r,
i
by A5, A6, RADIX_1:15;
:: thesis: verum end; end; end;
hence
DigA (Mmax r),
i >= DigA r,
i
;
:: thesis: verum
end;
hence
SDDec (Mmax r) >= SDDec r
by A2, RADIX_5:13; :: thesis: verum