
theorem Th1110:
Sum digits(825,10) = 15
proof
  thus Sum digits(825,10) = Sum <%5,2%>+Sum <%8%> by Th1109,AFINSQ_2:55
  .= (5 + 2) + Sum <%8%> by AFINSQ_2:54
  .= 7 + 8 by AFINSQ_2:53
  .= 15;
end;
