
theorem Th485:
Sum digits(1560,10) = 12
proof
  thus Sum digits(1560,10) = Sum <%0,6,5%>+Sum <%1%> by Th484,AFINSQ_2:55
  .= Sum <%0,6%> + Sum <%5%> + Sum <%1%> by AFINSQ_2:55
  .= (0 + 6) + Sum <%5%> + Sum <%1%> by AFINSQ_2:54
  .= (0 + 6 + 5) + Sum <%1%> by AFINSQ_2:53
  .= 11 + 1 by AFINSQ_2:53
  .= 12;
end;
