
theorem Th982:
Sum digits(828,10) = 18
proof
  thus Sum digits(828,10) = Sum <%8,2%>+Sum <%8%> by Th981,AFINSQ_2:55
  .= (8 + 2) + Sum <%8%> by AFINSQ_2:54
  .= 10 + 8 by AFINSQ_2:53
  .= 18;
end;
