
theorem Th304:
Sum digits(361,10) = 10
proof
  thus Sum digits(361,10) = Sum <%1,6%>+Sum <%3%> by Th303,AFINSQ_2:55
  .= (1 + 6) + Sum <%3%> by AFINSQ_2:54
  .= 7 + 3 by AFINSQ_2:53
  .= 10;
end;
