
theorem Th76:
Sum digits(132,10) = 6
proof
  thus Sum digits(132,10) = Sum <%2,3%>+Sum <%1%> by Th75,AFINSQ_2:55
  .= (2 + 3) + Sum <%1%> by AFINSQ_2:54
  .= 5 + 1 by AFINSQ_2:53
  .= 6;
end;
