[henshin-dev] Difference between require and forbid?

[Jens Bürger <jens.buerger@xxxxxxxxxxxxxxxxx>]

Hello everyone,

what is the exact difference between the require and forbid-action?

Regarding the movies example of
http://www.ckrause.org/2013/12/path-constraints-in-henshin.html

the matching seems more restrictive in a way that not every permutation 
of three movies generates a separate match, but is there a place where 
this is made more clear?

The Henshin page of the Henshin wiki doesn't go into detail here either, 
because it even says
"Regarding semantics, PACs could be also specified using «preserve»":

http://wiki.eclipse.org/Henshin_Graphical_Editor


Thanks in advance,

Jens