pfsg-format

[Solen Quiniou]

Hi !
I've got one question about the pfsg format : is the transition cost, 
between 2 states, considered to be 10000.5 times the log-probability of 
the bigram corresponding to the 2 states ?
Because, when I use a language model made from an ARPA file (by using 
the NgramLM class) to compute the probability of a word (my language 
model is based on letters) and when I use a language model made from a 
PFSG file (I convert the ARPA thanks to the make-ngram-pfsg script and 
then by using the LatticeLM class), I don't have the same 
log-probability from both representations. Why is there a difference ? 
Since I convert the ARPA file into a PFSG file, it should be the same.

Thanks for answering.

Solen.