Exempel på rewriting

• The residuation principle is based on the idea of delaying function calls until they are sufficiently instantiated for a deterministic evaluation by rewriting.

• The advantage of rewriting the boundary conditions in this form is that the equations become separated into groups of independent equations which are easily solved.

• Different controls are equipped with different reaction rules, often called rewriting rules in syntactic or graphical systems.

• Furthermore, there are unary rules rewriting this start category into each of the relevant maximal projections.

• A rewriting in a set will be redundant if the data it asks for are already contained by the other rewritings in the set.

• For example, text rewriting in translation and compiler construction is based on tokenized text, hence problems with overlapping originals do not occur.

• We use a small-step operational semantics in the form of a single-step rewriting system that defines a (non-deterministic) normal-order reduction.

• All these observations also hold for rewriting modulo associativity and commutativity.

• In the following we will consider only term graphs in flat form and without useless equations (garbage), which we remove systematically during rewriting.

• Both classes of languages share concepts like pattern matching (first-order versus higher-order), (tree or graph) rewriting, guards (or conditions), sometimes "where" blocks and "let" expressions.

• It would be of interest to know whether such groups must have a finite convergent rewriting system.

• The rewriting structure is checked for consistency with the term.

• Conditional rewriting logic as a unified model of concurrency.

• Both conditional and non-conditional term rewriting are covered; but the treatment is still mathematical rather than implementation based.

• As in standard term rewriting, we can use local confluence and strong normalisation to prove the confluence of a relation.