[Haskell-cafe] Use Haskell to extract GXL file (GXL representation)

Dear you all, Currently, I am working with GXL file (Graph eXchange Language). GXL is a sublanguage of XML and its syntax is based XML DTD. In my work, I use GXL representation to represent a quantification: forall(x:Z|x = 3 and x^2 - 3x + 2 =0) My objective is to write a Haskell module to extract the content of the GXL file such that a computer algebra system (e.g, Matlab) or a prover theorem (e.g, ICS) can read the content of GXL file. Anybody