
theorem Th137:
Sum digits(14,10) = 5
proof
  thus Sum digits(14,10) = Sum <%4%>+Sum <%1%> by Th136,AFINSQ_2:55
  .= 4 + Sum <%1%> by AFINSQ_2:53
  .= 4+1 by AFINSQ_2:53
  .= 5;
end;
