How to count facts?

%?- findall(t, a(_), Ls), length(Ls, L).
%@ Ls = [t, t, t, t],
%@ L = 4

http://coding.derkeiler.com/Archive/Prolog/comp.lang.prolog/2007-09/msg00175.html

Add a fact iteractively in prolog?

use assert

http://ubuntuforums.org/showthread.php?t=512827

Prolog script

http://www.lix.polytechnique.fr/~catuscia/teaching/prolog/Manual/sec-6.html

http://www.lix.polytechnique.fr/~catuscia/teaching/prolog/Manual/sec-2.7.html#sec:2.7.2.1

Compilation

http://ce.sharif.edu/courses/83-84/1/ce417/resources/root/Softwares/SWI.HTM

All-solutions predicates

https://www.cs.tcd.ie/courses/csll/sicstus/All-Solutions.html

SWI-Prolog prompts using "more?"

http://ftp.swi.psy.uva.nl/twiki/pl/bin/view/FAQ/MorePrompt

http://www.cse.unsw.edu.au/~billw/prologdict.html#More