Efficient Semantics-Based Compliance Checking Using LTL Formulae and Unfolding

Algorithm 3

Transforming an annotated CFP into a set of conflict-free annotated CFPs.

function  𝐺𝑒𝑡𝐴𝑙𝑙𝐸𝑥𝑒𝑐𝑢𝑡𝑖𝑜𝑛𝑠

Input: An annotated CFP 𝑈=(𝜌,𝐿) where 𝜌=(𝐵,𝐸,𝐹) and 𝐿⊆𝐸×𝐸

Output: A set of annotated CFPs 𝕌

begin

 𝕌∶=∅;

 Γ∶=∅;

 /* compute CFPs from each of the co-sets of leaf conditions */

 CS:= GetLeafCondCoSets(𝜌);

 for  𝑐𝑠∈𝐶𝑆  do

  Γ∪∶={ComputeCFP(𝜌,𝑐𝑠)};

 /* generate annotated CFPs from the above (conflict-free) CFPs */

 Γ_𝑡𝑚𝑝:= Γ;

 repeat

  Select 𝜌^′∈Γ_𝑡𝑚𝑝;

  𝐿^′∶=∅;

  𝐸_{𝑐𝑢𝑡𝑜𝑓𝑓}:= GetCutoffEvents(𝜌^′);

  𝑓_{𝑢𝑝𝑑𝑎𝑡𝑒}:= FALSE; /* the flag changes to TRUE if there are CFP updates */

  while  𝐸_{𝑐𝑢𝑡𝑜𝑓𝑓}≠∅∧¬𝑓_{𝑢𝑝𝑑𝑎𝑡𝑒}  do

   Select 𝑒_𝑐𝑢𝑡∈𝐸_{𝑐𝑢𝑡𝑜𝑓𝑓};

   𝑒_{𝑐𝑜𝑛𝑡}:= GetContinuationEvent(𝐿,𝑒_𝑐𝑢𝑡);

   if  𝑒_{𝑐𝑜𝑛𝑡}∈𝜌^′⋅𝐸  then

    𝐿^′∪∶={(𝑒_𝑐𝑢𝑡,𝑒_{𝑐𝑜𝑛𝑡})};

   else

    Γ_𝑎𝑑𝑑:= GetUpdatedCFPs(𝜌^′,Γ,𝑒_𝑐𝑢𝑡,𝑒_{𝑐𝑜𝑛𝑡}); /* see Algorithm 4 */

    Γ⧵∶={𝜌^′};

    Γ∪∶=Γ_𝑎𝑑𝑑;

    𝐿_𝑎𝑑𝑑:= GetLinks_to(𝐿,𝑒_{𝑐𝑜𝑛𝑡})⧵{(𝑒_𝑐𝑢𝑡,𝑒_{𝑐𝑜𝑛𝑡})};

    for  𝑒  𝑤ℎ𝑒𝑟𝑒  (𝑒,𝑒_{𝑐𝑜𝑛𝑡})∈𝐿^′  do

     𝐿_𝑎𝑑𝑑∪∶={(𝑒,𝑒_𝑐𝑢𝑡)}

    𝐿⧵∶={(𝑒_𝑐𝑢𝑡,𝑒_{𝑐𝑜𝑛𝑡})};

    𝐿∪∶=𝐿_𝑎𝑑𝑑;

    𝑓_{𝑢𝑝𝑑𝑎𝑡𝑒}:= TRUE; /* set the flag to TRUE upon CFP updates */

    Γ_𝑡𝑚𝑝∪∶=Γ_𝑎𝑑𝑑; /* add to the remaining CFPs for link annotations */

   𝐸_{𝑐𝑢𝑡𝑜𝑓𝑓}⧵∶={𝑒_𝑐𝑢𝑡};

  if ¬𝑓_{𝑢𝑝𝑑𝑎𝑡𝑒}  then

   𝕌∪∶={(𝜌^′,𝐿^′)};

  Γ_𝑡𝑚𝑝⧵∶={𝜌^′}

 until  Γ_𝑡𝑚𝑝=∅;