
theorem Th779:
Sum digits(682,10) = 16
proof
  thus Sum digits(682,10) = Sum <%2,8%>+Sum <%6%> by Th778,AFINSQ_2:55
  .= (2 + 8) + Sum <%6%> by AFINSQ_2:54
  .= 10 + 6 by AFINSQ_2:53
  .= 16;
end;
