
theorem Th994:
Sum digits(1035,10) = 9
proof
  thus Sum digits(1035,10) = Sum <%5,3,0%>+Sum <%1%> by Th993,AFINSQ_2:55
  .= Sum <%5,3%> + Sum <%0%> + Sum <%1%> by AFINSQ_2:55
  .= (5 + 3) + Sum <%0%> + Sum <%1%> by AFINSQ_2:54
  .= (5 + 3 + 0) + Sum <%1%> by AFINSQ_2:53
  .= 8 + 1 by AFINSQ_2:53
  .= 9;
end;
