
theorem Th250:
Sum digits(340,10) = 7
proof
  thus Sum digits(340,10) = Sum <%0,4%>+Sum <%3%> by Th249,AFINSQ_2:55
  .= (0 + 4) + Sum <%3%> by AFINSQ_2:54
  .= 4 + 3 by AFINSQ_2:53
  .= 7;
end;
