Function Traces explore (Class α, Trans , Classes )
if ) then
if then
   return
end if
return  
end if
if ( ) then
return
end if
Traces ;
for all   s.t  
do
=
end for     contains all bad sequences of  α.}
if  ( ) then
return  
end if
if   then
return
end if
return
Algorithm 2: On-the-fly algorithm for the safety control of TPN-Part II.