
theorem Th332:
Sum digits(627,10) = 15
proof
  thus Sum digits(627,10) = Sum <%7,2%>+Sum <%6%> by Th331,AFINSQ_2:55
  .= (7 + 2) + Sum <%6%> by AFINSQ_2:54
  .= 9 + 6 by AFINSQ_2:53
  .= 15;
end;
