reserve p,q,r for FinSequence;
reserve u,v,x,y,y1,y2,z for object, A,D,X,Y for set;
reserve i,j,k,l,m,n for Nat;

theorem
  p is one-to-one & rng p = {x} implies p = <* x *>
proof
  assume that
A1: p is one-to-one and
A2: rng p = {x};
  len p = 1 by A1,A2,Th94;
  hence thesis by A2,FINSEQ_1:39;
end;
