Two normal forms for link-connector pairs in NCL 3.0

Abstract

In this paper, we investigate the problem of normal forms for links and connectors in NCL 3.0. We identify two such forms, called the First and Second Normal Forms (NF1 and NF2), in which links and connectors appear in simple terms. We also present normalization procedures (proofs), which show that for every NCL 3.0 program, there is an equivalent program in each of the forms. The mere existence of NF1 and NF2 makes the semantic analysis of programs simpler. Moreover, the symmetry exhibited by these forms suggests that the same principle of arbitrarily ordered evaluation underlies both the evaluation of link conditions and the execution of nonsequential compound actions.

A rewriting logic semantics for NCL

“…Once all links in the NCL document are translated into rels, we simplify the rel set for a given document. This process of rel simplification follows the second normal form presented in [33]. We perform this simplification step in the document transformation in order to guarantee that no concurrence appear in the rel equations set.…”

A Synchronous Virtual Machine for Multimedia Presentations

“…A Micro NCL (or µNCL) program is an NCL program containing only media objects, properties, and links, and in which links are in a restricted (basic) format. More precisely, a µNCL program is an NCL 3.0 Raw Profile [130,131] program with neither content anchors nor contexts (the structuring concept of the language) and whose link-connector pairs are in the first normal form defined in [132]. 1,2 The next section, Section 6.1.1, defines the µNCL language, and the subsequent section, Section 6.1.2, details the conversion of µNCL programs to Plain Smix.…”