minor technical on A.3 Keywords

Annex A.3 Keywords
it does not make sense that the keyword 'a' can only
be written in lowercase, unlike all other keywords.  Evidently you have
a precedent in Turtle and N3.  However, it is not an incompatibility to
allow 'A' and 'a' to be synonyms in SPARQL even if the uppercase form is
not found in Turtle or N3; this just makes you a superset of them.

Fred Zemke