Phase Transitions of Contingent Planning Problem

Algorithm 1

Contingent plan-nonexistence algorithm.

Algorithm CONTINGENT PLAN-NONEXITENCE (𝐒,𝐀,𝐎,𝐈,𝐆)

 for each  𝑠∈𝐈

  if 𝑝𝑟𝑒(𝐀)⊄𝑠;

  then return  failure;

 endfor

 for each  𝑔∈𝐆

  if 𝑔⊄𝑒𝑓𝑓(𝐀)

  then return  failure;

 endfor

 for each  𝑜∈𝐎

Bs_𝑇=𝐈∩𝜑⁻(𝑜);

Bs_𝐹=𝐈∩𝜑⁻(𝑜⁻);

  for each  𝑠∈Bs_𝑇

   if 𝑝𝑟𝑒(𝐀)⊂𝑠;

   then return don’t know;

  endfor

  for each 𝑠^′∈Bs_𝐹

   if 𝑝𝑟𝑒(𝐀)⊂𝑠^′;

   then return don’t know;

  endfor

 endfor

 return  failure;

end