State space visualization examples

Alternating Bit Protocol

This is a visualisation of 3643 states and 11115 transitions of the MCAlternatingBit.tla model distributed with the model checker, loaded with ProB.

The goal predicate rBit=1 was used; those states satisfying this predicate are shown in orange.

MCAlternatingBit sfdp.png


The main file of the model is:

--------------------------- MODULE MCAlternatingBit -------------------------
EXTENDS AlternatingBit, TLC

INSTANCE ABCorrectness 

CONSTANTS msgQLen, ackQLen

SeqConstraint == /\ Len(msgQ) \leq msgQLen
                 /\ Len(ackQ) \leq ackQLen

SentLeadsToRcvd == \A d \in Data : (sent = d) /\ (sBit # sAck) ~> (rcvd = d)
=============================================================================

ImpliedAction == [ABCNext]_cvars

TNext == WF_msgQ(~ABTypeInv')
TProp == \A d \in Data : (sent = d) => [](sent = d)

CSpec == ABSpec /\ TNext

DataPerm == Permutations(Data)
==============================================================