
theorem Th940:
Sum digits(230,10) = 5
proof
  thus Sum digits(230,10) = Sum <%0,3%>+Sum <%2%> by Th939,AFINSQ_2:55
  .= (0 + 3) + Sum <%2%> by AFINSQ_2:54
  .= 3 + 2 by AFINSQ_2:53
  .= 5;
end;
