
theorem Th248:
Sum digits(323,10) = 8
proof
  thus Sum digits(323,10) = Sum <%3,2%>+Sum <%3%> by Th247,AFINSQ_2:55
  .= (3 + 2) + Sum <%3%> by AFINSQ_2:54
  .= 5 + 3 by AFINSQ_2:53
  .= 8;
end;
