
theorem Th1190:
Sum digits(2225,10) = 11
proof
  thus Sum digits(2225,10) = Sum <%5,2,2%>+Sum <%2%> by Th1189,AFINSQ_2:55
  .= Sum <%5,2%> + Sum <%2%> + Sum <%2%> by AFINSQ_2:55
  .= (5 + 2) + Sum <%2%> + Sum <%2%> by AFINSQ_2:54
  .= (5 + 2 + 2) + Sum <%2%> by AFINSQ_2:53
  .= 9 + 2 by AFINSQ_2:53
  .= 11;
end;
