
theorem Th952:
Sum digits(414,10) = 9
proof
  thus Sum digits(414,10) = Sum <%4,1%>+Sum <%4%> by Th951,AFINSQ_2:55
  .= (4 + 1) + Sum <%4%> by AFINSQ_2:54
  .= 5 + 4 by AFINSQ_2:53
  .= 9;
end;
