reserve i,j,k,n,m for Nat,
  x,y,z,y1,y2 for object, X,Y,D for set,
  p,q for XFinSequence;
reserve k1,k2 for Nat;
reserve D for non empty set,
  F,G for XFinSequence of D,
  b for BinOp of D,
  d,d1,d2 for Element of D;
reserve F for XFinSequence,
        rF,rF1,rF2 for real-valued XFinSequence,
        r for Real,
        cF,cF1,cF2 for complex-valued XFinSequence,
        c,c1,c2 for Complex;

theorem
  for D being set, d be Element of D^omega holds FlattenSeq <%d%> = d
proof
  let D be set, d be Element of D^omega;
  ex g being BinOp of D^omega st
  (for p, q being Element of D^omega holds g.(p,q) = p^q) &
  FlattenSeq <%d%> = g "**" <% d %> by Def10;
  hence thesis by Th37;
end;
