Functions to reify and dereify a graph.
These functions should be perfect inverses of each other.
 
The strategy used is different from that of the reifier
in notation3.py, that tries to reify what it outputs.
This simply puts the reification into the sink given,
or a new one, depending on the function called.
$Id: reify.py,v 1.17 2007/06/26 02:36:15 syosi Exp $

Modules
		diag uripath

Functions
		dereification(x, f, sink, bnodes={}, xList=[]) dereify(formula, sink=None, xList=[]) #### Alternative method # Shortcuts are too messy and don't work with lists flatten(formula) Flatten a formula   This will minimally change a formula to make it valid RDF flattening a flattened formula should thus be the unity reify(formula) Reify a formula   Returns an RDF formula with the same semantics as the given formula unflatten(formula, sink=None) Undo the effects of the flatten function.   Note that this still requires helper methods scattered throughout the Term heriarchy.    Our life is made much more difficult by the necessity of removing all triples that have been dereified --- this required a modification to dereification()

Data
		ALL4 = (0, 1, 2, 3) CONTEXT = 0 Mixin = <mixin.mixinClass object> OBJ = 3 PARTS = (1, 2, 3) PRED = 1 RDF_type_URI = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type' REIFY_NS = 'http://www.w3.org/2004/06/rei#' SUBJ = 2 owlOneOf = 'http://www.w3.org/2002/07/owl#oneOf' rAnonymousNode = <mixin.mixinClass object> rFormula = <mixin.mixinClass object> rLabelledNode = <mixin.mixinClass object> rList = <mixin.mixinClass object> rLiteral = <mixin.mixinClass object> rN3Set = <mixin.mixinClass object> rTerm = <mixin.mixinClass object> reifyNS = 'http://www.w3.org/2004/06/rei#'