
theorem Th1084:
Sum digits(250,10) = 7
proof
  thus Sum digits(250,10) = Sum <%0,5%>+Sum <%2%> by Th1083,AFINSQ_2:55
  .= (0 + 5) + Sum <%2%> by AFINSQ_2:54
  .= 5 + 2 by AFINSQ_2:53
  .= 7;
end;
