
theorem Th734:
Sum digits(147,10) = 12
proof
  thus Sum digits(147,10) = Sum <%7,4%>+Sum <%1%> by Th733,AFINSQ_2:55
  .= (7 + 4) + Sum <%1%> by AFINSQ_2:54
  .= 11 + 1 by AFINSQ_2:53
  .= 12;
end;
