
theorem Th736:
Sum digits(189,10) = 18
proof
  thus Sum digits(189,10) = Sum <%9,8%>+Sum <%1%> by Th735,AFINSQ_2:55
  .= (9 + 8) + Sum <%1%> by AFINSQ_2:54
  .= 17 + 1 by AFINSQ_2:53
  .= 18;
end;
