
theorem Th1094:
Sum digits(450,10) = 9
proof
  thus Sum digits(450,10) = Sum <%0,5%>+Sum <%4%> by Th1093,AFINSQ_2:55
  .= (0 + 5) + Sum <%4%> by AFINSQ_2:54
  .= 5 + 4 by AFINSQ_2:53
  .= 9;
end;
