
theorem Th435:
Sum digits(1060,10) = 7
proof
  thus Sum digits(1060,10) = Sum <%0,6,0%>+Sum <%1%> by Th434,AFINSQ_2:55
  .= Sum <%0,6%> + Sum <%0%> + Sum <%1%> by AFINSQ_2:55
  .= (0 + 6) + Sum <%0%> + Sum <%1%> by AFINSQ_2:54
  .= (0 + 6 + 0) + Sum <%1%> by AFINSQ_2:53
  .= 6 + 1 by AFINSQ_2:53
  .= 7;
end;
