Nominal and locational predication overlap in their encoding. Both constructions have copula-less forms, i.e. they have forms which do not require either a resumptive pronoun or a copula verb top (< stop). In both constructions, the use of the resumptive pronoun is also optional. However, the copula verb may be used in locational predication, which is the point of difference between the constructions.
Source: Meakins 2011: 424
Source: Meakins 2007-2008
Source: Meakins 2003-2006
Source: Meakins 2011: 241