
theorem Th930:
Sum digits(115,10) = 7
proof
  thus Sum digits(115,10) = Sum <%5,1%>+Sum <%1%> by Th929,AFINSQ_2:55
  .= (5 + 1) + Sum <%1%> by AFINSQ_2:54
  .= 6 + 1 by AFINSQ_2:53
  .= 7;
end;
