
theorem Th1088:
Sum digits(325,10) = 10
proof
  thus Sum digits(325,10) = Sum <%5,2%>+Sum <%3%> by Th1087,AFINSQ_2:55
  .= (5 + 2) + Sum <%3%> by AFINSQ_2:54
  .= 7 + 3 by AFINSQ_2:53
  .= 10;
end;
