let domImpl = Gdome.domImplementation ()
let helm_ns = Gdome.domString "http://www.cs.unibo.it/helm"
let xlink_ns = Gdome.domString "http://www.w3.org/1999/xlink"
let domImpl = Gdome.domImplementation ()
let helm_ns = Gdome.domString "http://www.cs.unibo.it/helm"
let xlink_ns = Gdome.domString "http://www.w3.org/1999/xlink"