
theorem Th1352:
Sum digits(4675,10) = 22
proof
  thus Sum digits(4675,10) = Sum <%5,7,6%>+Sum <%4%> by Th1351,AFINSQ_2:55
  .= Sum <%5,7%> + Sum <%6%> + Sum <%4%> by AFINSQ_2:55
  .= (5 + 7) + Sum <%6%> + Sum <%4%> by AFINSQ_2:54
  .= (5 + 7 + 6) + Sum <%4%> by AFINSQ_2:53
  .= 18 + 4 by AFINSQ_2:53
  .= 22;
end;
