
theorem Th705:
Sum digits(3760,10) = 16
proof
  thus Sum digits(3760,10) = Sum <%0,6,7%>+Sum <%3%> by Th704,AFINSQ_2:55
  .= Sum <%0,6%> + Sum <%7%> + Sum <%3%> by AFINSQ_2:55
  .= (0 + 6) + Sum <%7%> + Sum <%3%> by AFINSQ_2:54
  .= (0 + 6 + 7) + Sum <%3%> by AFINSQ_2:53
  .= 13 + 3 by AFINSQ_2:53
  .= 16;
end;
