CA with Inputs and Outputs

[Alireza Farhadi]

Dear Member, 

I recently read a new paper of Natallia Kokash et al. (http://homepages.cwi.nl/~kokash/documents/PACO11.pdf) about input output conformance testing, in the example1, two Reo networks had brought that were consisted of a Replicator, a Synch and a FIFO1 channel. first network relates to a specification and next is its wrong implementation. 

In continue constraint automata with inputs and outputs for this specification and its wrong implementation are depicted. my question is how to construct these automaton. 

for example when I trace specification automata for this sequence 0-3-9-0 I understand behavior of it because we had 1 request in A, C and B ports (0-3) and in consequence we had response in A and C ports (3-9) and finally in B port (9-0) but when I trace 0-2-8-9-0, after one request and response on A and C ports (0-2,2-8) we encounter with 2 response on B port(8-9,9-8). Why dose this happen?

Picture of example1 Reo networks and related CA with Inputs and Outputs is attached.

Regards,

Alireza Farhadi