Should sameValue be callable?

[afs]

sameValue(arg1, arg2) tests whether two RDF literals arg1 and arg2 represent the same value as well as testing for sameness on URIs blank nodes and, recursively, triple terms.

It is part of the dispatch for the equality test = and provides an extension point for support for additional datatypes beyond "same term implies same value" implied by any lexical-to-value mapping. In the case of xsd:double and xsd:float NaNs term identity does not imply numeric-equality.

See issue #187 and PR #194.

Should sameValue be callable in standard SPARQL? That is, add the function name to the grammar (c.f. sameTerm)?