21. Well-formedness criteria were used to supply additional constraints on operations beyond what was defined by the abstract syntax . 22. It may help to think of the abstract syntax tree of a programming language and algebraic data types. 23. The Tree Grammar Engine ( TGE ) then converts these into Parrot Abstract Syntax Trees ( PAST ). 24. BIND is based on a data specification written using Abstract Syntax Notation 1 ( ASN . 1 ) language. 25. An abstract semantic graph is typically constructed from an abstract syntax tree by a process of enrichment and abstraction. 26. An example of this intermediate representation could be something like an Abstract Syntax Tree or a Directed Acyclic Graph. 27. ASN . 1 defines the abstract syntax of information but does not restrict the way the information is encoded. 28. The tree building operators were used in the grammar rules directly transforming the input into an abstract syntax tree. 29. Because of this, a parser usually outputs more than a yes / no answer, typically an abstract syntax tree. 30. The compactness requires that the decoder knows the complete abstract syntax of the data structure to be decoded, however.
