A discussion of the functional setting customarily adopted in General Relativity (GR) is proposed. This is based on the introduction of the notion of nonlocal point transformations (NLPTs). While allowing the extension of the traditional concept of GR-reference frame. NLPTs are important because they permit the explicit determination of the map between intrinsically different and gene... https://www.littletreehouselanes.shop/product-category/backpack-nappy-bag/