reserve i,j,n,k,m for Nat,
     a,b,x,y,z for object,
     F,G for FinSequence-yielding FinSequence,
     f,g,p,q for FinSequence,
     X,Y for set,
     D for non empty set;
reserve
  B,A,M for BinOp of D,
  F,G for D* -valued FinSequence,
  f for FinSequence of D,
  d,d1,d2 for Element of D;
reserve
  F,G for non-empty non empty FinSequence of D*,
  f for non empty FinSequence of D;
reserve f,g for FinSequence of D,
        a,b,c for set,
        F,F1,F2 for finite set;

theorem Th77:
  for E be Enumeration of {x} holds E = <*x*>
proof
  let E be Enumeration of {x};
A1: len E=card {x} =1 by CARD_1:def 7;
  then 1 in dom E by FINSEQ_3:25;
  then E.1 in rng E by FUNCT_1:def 3;
  then E.1=x by TARSKI:def 1;
  hence thesis by A1,FINSEQ_1:40;
end;
