
theorem Th575:
Sum digits(2460,10) = 12
proof
  thus Sum digits(2460,10) = Sum <%0,6,4%>+Sum <%2%> by Th574,AFINSQ_2:55
  .= Sum <%0,6%> + Sum <%4%> + Sum <%2%> by AFINSQ_2:55
  .= (0 + 6) + Sum <%4%> + Sum <%2%> by AFINSQ_2:54
  .= (0 + 6 + 4) + Sum <%2%> by AFINSQ_2:53
  .= 10 + 2 by AFINSQ_2:53
  .= 12;
end;
