
theorem Th749:
Sum digits(242,10) = 8
proof
  thus Sum digits(242,10) = Sum <%2,4%>+Sum <%2%> by Th748,AFINSQ_2:55
  .= (2 + 4) + Sum <%2%> by AFINSQ_2:54
  .= 6 + 2 by AFINSQ_2:53
  .= 8;
end;
