Converting VALUES to SPARQL algebra

I was wondering how one converts a query contain VALUES such as in
http://www.w3.org/TR/sparql11-query/#inline-data to SPARQL algebra?
The spec just mentions 'The result is a multiset of solution mappings
'data'.'.
The validator at http://www.sparql.org/query-validator.html outputs this
as: (table (vars ?book) (row [?book :book1]) (row [?book :book3]) ) but
nowhere does the spec define table or row (as far as I can see).
Are the table/row elements just a custom implementation or is there a
different spec somewhere that defines these?

Thanks,
Joachim