
theorem Th956:
Sum digits(529,10) = 16
proof
  thus Sum digits(529,10) = Sum <%9,2%>+Sum <%5%> by Th955,AFINSQ_2:55
  .= (9 + 2) + Sum <%5%> by AFINSQ_2:54
  .= 11 + 5 by AFINSQ_2:53
  .= 16;
end;
