reserve k,m,n for Nat,
  i1,i2,i3 for Integer,
  e for set;
reserve i,k,m,n,p,x,y for Nat;
reserve a for Tuple of n,(k-SD);

theorem Th16:
  for x be Tuple of 1,INT st x/.1 = m holds x = <*m*>
proof
  let x be Tuple of 1,INT;
  assume
A1: x/.1 = m;
A2: len x = 1 by CARD_1:def 7;
  then x/.1 = x.1 by FINSEQ_4:15;
  hence thesis by A1,A2,FINSEQ_1:40;
end;
