
theorem Th984:
Sum digits(851,10) = 14
proof
  thus Sum digits(851,10) = Sum <%1,5%>+Sum <%8%> by Th983,AFINSQ_2:55
  .= (1 + 5) + Sum <%8%> by AFINSQ_2:54
  .= 6 + 8 by AFINSQ_2:53
  .= 14;
end;
