reserve X for BCI-algebra;
reserve I for Ideal of X;
reserve a,x,y,z,u for Element of X;
reserve f,f9,g for sequence of  the carrier of X;
reserve j,i,k,n,m for Nat;

theorem
  ((0.X,x) to_power (m+n))` = ((0.X,x)to_power m)`\(0.X,x)to_power n
proof
  ((0.X,x)to_power (m+n))` =(((0.X,x)to_power m)\((0.X,x)to_power n)`)` by Th13
    .=(((0.X,x)to_power m)`)\(((0.X,x)to_power n)`)` by BCIALG_1:9;
  hence thesis by Th12;
end;
