Lexical-to-value mapping is not a "partial mapping" #66
Description
This issue is about the following sentence in Sec.7 of RDF Semantics.
A datatype is understood to define a partial mapping, called the lexical-to-value mapping, from a lexical space (a set of character strings) to values.
This sentence is incorrect in the sense that, by the definition of the notion of a lexical-to-value mapping in RDF Concepts, it is not a partial mapping but a total mapping (or, simply, a function). The relevant part of the definition is that is says: "Each member of the lexical space is paired with ..."
Related to this issue, the following sentence (in the same paragraph as the one quoted above) is also not particularly accurate.
An ill-typed literal is one whose datatype IRI is recognized, but whose character string is assigned no value by the lexical-to-value mapping for that datatype.
To fix this issue, I suggest to change the first sentence quoted above as follows:
A datatype is understood to define a function, called the lexical-to-value mapping, from a lexical space (a set of character strings) to values.
And the second sentence quoted above may be changed as follows:
An ill-typed literal is one whose datatype IRI is recognized, but whose character string is not in the lexical space of the datatype identified by that IRI and, thus, is not in the domain of the lexical-to-value mapping of that datatype.