# Pack pac updated to pac-1.6.8

**URL:** <https://swi-prolog.discourse.group/t/pack-pac-updated-to-pac-1-6-8/5835>\
**Category:** Pack\
**Tags:** zdd\
**Created:** [October 7, 2022, 8:23pm UTC](https://swi-prolog.discourse.group/t/pack-pac-updated-to-pac-1-6-8/5835 "2022-10-07T20:23:34Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![kuniaki.mukai](https://avatars.discourse-cdn.com/v4/letter/k/c67d28/32.png) [@kuniaki.mukai](https://swi-prolog.discourse.group/u/kuniaki.mukai)\
**Post date:** [October 7, 2022, 8:23pm UTC](https://swi-prolog.discourse.group/t/pack-pac-updated-to-pac-1-6-8/5835/1 "2022-10-07T20:23:34Z")

</div>

I have updated pack pac to v1.6.8. If the log below is reproduced on your terminal, then perhaps you can play around some zdd programming, referring to a block of comment lines in library(‘pac/zdd/zdd.pl’) as cheat sheet.

```prolog
% swipl
?- pack_install(pac).
% Contacting server at https://www.swi-prolog.org/pack/query ... ok
% Pack `pac' is already installed @1.6.8

?- use_module(library(pac)).

?- use_module(zdd(zdd)).

zdd: ?- use_state(S), X<<pow([a,b]), cofact(X, t(A, L, R), S), psa(X, S), psa(L, S), psa(R, S).
 zid = 3
	[]
	[b]
	[a]
	[a,b]
-------------------
 zid = 2
	[]
	[b]
-------------------
 zid = 2
	[]
	[b]
-------------------
S = ..,
X = 3,
A = a,
L = R, R = 2.

```