  In SPARQL, the query forms SELECT and CONSTRUCT have been the subject of
several studies, both theoretical and practical. However, the composition of
such queries and their interweaving when forming involved nested queries has
not yet received much interest in the literature. We mainly tackle the problem
of composing such queries. For this purpose, we introduce a language close to
SPARQL where queries can be nested at will, involving either CONSTRUCT or
SELECT query forms and provide a formal semantics for it. This semantics is
based on a uniform interpretation of queries. This uniformity is due to an
extension of the notion of RDF graphs to include isolated items such as
variables. As a key feature of this work, we show how classical SELECT queries
can be easily encoded as a particular case of CONSTRUCT queries.
