reserve k,n for Nat,
  x,y,z,y1,y2 for object,X,Y for set,
  f,g for Function;
reserve p,q,r,s,t for XFinSequence;
reserve D for set;
reserve i for Nat;
reserve m for Nat,
        D for non empty set;
reserve l for Nat;
reserve M for Nat;
reserve m,n for Nat;

theorem
 Shift(p^q,n) c= X implies Shift(q,n+card p) c= X
 proof assume
A1: Shift(p^q,n) c= X;
   Shift(q,n+card p) c= Shift(p^q,n) by Th78;
  hence thesis by A1;
 end;
