
theorem Th352:
Sum digits(817,10) = 16
proof
  thus Sum digits(817,10) = Sum <%7,1%>+Sum <%8%> by Th351,AFINSQ_2:55
  .= (7 + 1) + Sum <%8%> by AFINSQ_2:54
  .= 8 + 8 by AFINSQ_2:53
  .= 16;
end;
