
theorem Th350:
Sum digits(798,10) = 24
proof
  thus Sum digits(798,10) = Sum <%8,9%>+Sum <%7%> by Th349,AFINSQ_2:55
  .= (8 + 9) + Sum <%7%> by AFINSQ_2:54
  .= 17 + 7 by AFINSQ_2:53
  .= 24;
end;
