
theorem Th342:
Sum digits(722,10) = 11
proof
  thus Sum digits(722,10) = Sum <%2,2%>+Sum <%7%> by Th341,AFINSQ_2:55
  .= (2 + 2) + Sum <%7%> by AFINSQ_2:54
  .= 4 + 7 by AFINSQ_2:53
  .= 11;
end;
