
theorem Th655:
Sum digits(3260,10) = 11
proof
  thus Sum digits(3260,10) = Sum <%0,6,2%>+Sum <%3%> by Th654,AFINSQ_2:55
  .= Sum <%0,6%> + Sum <%2%> + Sum <%3%> by AFINSQ_2:55
  .= (0 + 6) + Sum <%2%> + Sum <%3%> by AFINSQ_2:54
  .= (0 + 6 + 2) + Sum <%3%> by AFINSQ_2:53
  .= 8 + 3 by AFINSQ_2:53
  .= 11;
end;
