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,i
then DigA (Mmax r),i = r . i by A1, A3, A4, Def3
.= DigA r,i by A3, RADIX_1:def 3 ;
hence DigA (Mmax r),i >= DigA r,i ; :: thesis: verum
end;
suppose i < m ; :: thesis: DigA (Mmax r),i >= DigA r,i
then 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