
theorem Th781:
Sum digits(704,10) = 11
proof
  thus Sum digits(704,10) = Sum <%4,0%>+Sum <%7%> by Th780,AFINSQ_2:55
  .= (4 + 0) + Sum <%7%> by AFINSQ_2:54
  .= 4 + 7 by AFINSQ_2:53
  .= 11;
end;
