Assignment 1 is available here.
The PNFG compiler is here, and the NFG interpreter is here.
To compiler a game foo.pnfg:
java -cp pnfg.jar pnfg.Main -nfg foo.pnfg > foo.nfg
To run a compiled game:
java -cp nfg.jar nfg.Main foo.nfg
An example pnfg version of COD is here.
nb: The above PNFG compiler is a stable but older version that does not work with pnfg files in DOS format. You can
also try pnfg2.jar, a newer snapshot, which should handle CR/LF linefeeds properly (if you encounter bugs let me know!).
An example plot DAG can be seen here (as a "Puzzle Structure Chart").
Further documentation on PNFG can be found in Félix Martineau's MSc thesis, and this paper.