Attribute grammars (AGs) are known to be a good formalism for semantic
analysis and translation. However, debugging AGs is not simple due to
the specific difficulty of AGs, such as recursive grammar structure
and attribute dependency. In this paper, a new systematic debugging
method of AGs is proposed. Our approach is, in principle, based on
algorithmic debugging for AGs proposed before, but is more general.
This easily enables integration of various query-based systematic
debugging methods including slice based method.  The proposed method 
has been implemented in Aki, a debugger for AG description. We evaluate
our new approach by experiments using Aki, which shows the usability of
our debugging method.