If a given term was a skolemized named node for the given source id,
deskolemize it again to a blank node.
If the given term was a skolemized named node for another source, return false.
If the given term was not a skolemized named node, return the original term.
If a given term was a skolemized named node for the given source id, deskolemize it again to a blank node. If the given term was a skolemized named node for another source, return false. If the given term was not a skolemized named node, return the original term.