reserve x for set,
  i,j,k,n for Nat,
  K for Field;
reserve a,b,c,d for Element of K;

theorem Th15:
  Rev idseq 3 = <*3,2,1*>
proof
  reconsider h = <*2,3*> as FinSequence of NAT;
  <*1*>^h = <*1,2,3*> & Rev h = <*3,2*> by FINSEQ_1:43,FINSEQ_5:61;
  hence thesis by FINSEQ_2:53,FINSEQ_6:24;
end;
