
theorem Th1096:
Sum digits(525,10) = 12
proof
  thus Sum digits(525,10) = Sum <%5,2%>+Sum <%5%> by Th1095,AFINSQ_2:55
  .= (5 + 2) + Sum <%5%> by AFINSQ_2:54
  .= 7 + 5 by AFINSQ_2:53
  .= 12;
end;
