
theorem Th1130:
Sum digits(1175,10) = 14
proof
  thus Sum digits(1175,10) = Sum <%5,7,1%>+Sum <%1%> by Th1129,AFINSQ_2:55
  .= Sum <%5,7%> + Sum <%1%> + Sum <%1%> by AFINSQ_2:55
  .= (5 + 7) + Sum <%1%> + Sum <%1%> by AFINSQ_2:54
  .= (5 + 7 + 1) + Sum <%1%> by AFINSQ_2:53
  .= 13 + 1 by AFINSQ_2:53
  .= 14;
end;
