Efficient Semantics-Based Compliance Checking Using LTL Formulae and Unfolding

Algorithm 4

Updating a CFP with a cut-off event that links to a continuation event outside the CFP.

function  𝐺𝑒𝑡𝑈𝑝𝑑𝑎𝑡𝑒𝑑𝐶𝐹𝑃𝑠

Input: A CFP 𝜌=(𝐵,𝐸,𝐹), a set of CFPs Γ, a (cut-off) event 𝑒_𝑐𝑢𝑡, a (continuation) event 𝑒_{𝑐𝑜𝑛𝑡}

Output: A set of (updated) CFPs Γ^′

begin

 Γ^′∶=∅;

 /* get 𝜌  ready by removing the successor conditions of 𝑒_𝑐𝑢𝑡 (in 𝜌) */

 𝐵_𝑡𝑚𝑝:= iSuccessors(𝜌,𝑒_𝑐𝑢𝑡);

 𝜌⋅𝐵⧵∶=𝐵_𝑡𝑚𝑝;

 𝜌⋅𝐹⧵∶={𝑒_𝑐𝑢𝑡}×𝐵_𝑡𝑚𝑝;

 /* retrieve and process the CFPs that contain 𝑒_{𝑐𝑜𝑛𝑡}  in  Γ  */

 for  𝜌_𝑖∈Γ𝑤ℎ𝑒𝑟𝑒𝑒_{𝑐𝑜𝑛𝑡}∈𝜌_𝑖⋅𝐸  do

  /* remove from 𝜌  the part before 𝑒_{𝑐𝑜𝑛𝑡}, 𝑒_{𝑐𝑜𝑛𝑡}  itself, and the outgoing edges of 𝑒_{𝑐𝑜𝑛𝑡} */

   𝐻∶=  GetSubCFP_to(𝜌_𝑖,𝑒_{𝑐𝑜𝑛𝑡});

   𝜌_𝑖⋅𝐵⧵∶=𝐻⋅𝐵;

   𝜌_𝑖⋅𝐸⧵∶=𝐻⋅𝐸;

   𝜌_𝑖⋅𝐹⧵∶=𝐻⋅𝐹∪({𝑒_{𝑐𝑜𝑛𝑡}}×  iSuccessors(𝜌_𝑖,𝑒_{𝑐𝑜𝑛𝑡}));

  /* connect the above (updated) 𝜌  and 𝜌_𝑖  to 𝜌^′  */

   𝜌^′⋅𝐵∶=𝜌⋅𝐵∪𝜌_𝑖⋅𝐵;

   𝜌^′⋅𝐸∶=𝜌⋅𝐸∪𝜌_𝑖⋅𝐸;

   𝜌^′⋅𝐹∶=𝜌⋅𝐹∪𝜌_𝑖⋅𝐹∪({𝑒_𝑐𝑢𝑡}×  InitialConditions(𝜌_𝑖));

  Γ^′∪∶={𝜌^′}