The PENG ASP system supports the writing of textual specifications with the help of a smart text editor that possesses knowledge about the structure of the specification language. Specifications written in PENG ASP are incrementally translated into executable answer set programs and vice versa. That means the system allows for lossless semantic round-tripping between a human-readable specification and an answer set program. This functionality is achieved by a single bi-directional logic grammar that serves at the same time as a text processor and a text generator. We demonstrate that the PENG ASP system can be used to bridge the gap between a (seemingly) informal specification and an executable answer set program.