reserve
  a for natural Number,
  k,l,m,n,k1,b,c,i for Nat,
  x,y,z,y1,y2 for object,
  X,Y for set,
  f,g for Function;
reserve p,q,r,s,t for FinSequence;
reserve D for set;
reserve a, b, c, d, e, f for object;

theorem Th92:
  for A being finite set holds len canFS A = card A
proof
  let A be finite set;
  thus card canFS A = card dom canFS A by CARD_1:62
         .= card rng canFS A by CARD_1:70
         .= card A by FUNCT_2:def 3;
end;
