Norbert E. Fuchs

Specifications are (preferably) executable

The validation of specifications with respect to user requirements is extremely difficult. To ease the validation task and to give users immediate feedback on the behaviour of the future software, it was suggested that specifications should be made executable. However, Hayes and Jones [1] argue that executable specifications should be avoided because executability can restrict the expressiveness of specification langugages, and can adversely affect implementations. We argue for executable specifications by showing that non-executable formal specifications can be made executable on almost the same level of abstraction, and without essentially changing their structure. No new algorithms have to be introduced to get executability. Furthermore, we show that declarative specification languages combine high expressiveness and executability.

Attempto Controlled English for Knowledge Representation

Attempto Controlled English (ACE) is a controlled natural language, i.e. a precisely defined subset of English that can automatically and unambiguously be translated into first-order logic. ACE may seem to be completely natural, but is actually a formal language, concretely it is a first-order logic language with an English syntax. Thus ACE is human and machine understandable. ACE was originally intended to specify software, but has since been used as a general knowledge representation language in several application domains, most recently for the semantic web. ACE is supported by a number of tools, predominantly by the Attempto Parsing Engine (APE) that translates ACE texts into Discourse Representation Structures (DRS), a variant of first-order logic. Other tools include the Attempto Reasoner RACE, the AceRules system, the ACE View plug-in for the Protege ontology editor, AceWiki, and the OWL verbaliser.

Attempto Controlled English - Not Just Another Logic Specification Language

The specification language Attempto Controlled English (ACE) is a controlled natural language, i.e. a subset of standard English with a domain-specific vocabulary and a restricted grammar. The restriction of full natural language to a controlled subset is essential for ACE to be suitable for specification purposes. The main goals of this restriction are to reduce ambiguity and vagueness inherent in full natural language and to make ACE computer processable. ACE specifications can be unambiguously translated into logic specification languages, and can be queried and executed. In brief, ACE allows domain specialists to express specifications in familiar natural language and combine this with the rigour of formal specification languages.

Controlled Natural Language

This book constitutes the refereed proceedings of the 4th International Workshop on Controlled Natural Language, CNL 2014, held in Galway, Ireland, in August 2014. The 17 full papers and one invited paper presented were carefully reviewed and selected from 26 submissions. The topics include simplified language, plain language, formalized language, processable language, fragments of language, phraseologies, conceptual authoring, language generation, and guided natural language interfaces.

On controlled natural languages: properties and prospects

This collaborative report highlights the properties and prospects of Controlled Natural Languages (CNLs). The report poses a range of questions concerning the goals of the CNL, the design, the linguistic aspects, the relationships and evaluation of CNLs, and the application tools. In posing the questions, the report attempts to structure the field of CNLs and to encourage further systematic discussion by researchers and developers.

Bidirectional mapping between OWL DL and attempto controlled english

We describe ongoing work on a bidirectional mapping between Attempto Controlled English (ACE) and OWL DL. ACE is a well-studied controlled natural language, with a parser that converts ACE texts into Discourse Representation Structures (DRS). We show how ACE can be translated into OWL DL (by using the DRS as interlingua) and how OWL DL can be verbalized in ACE. This mapping renders ACE an interesting companion to existing OWL front-ends.

Reasoning in Attempto Controlled English

Attempto Controlled English (ACE) – a subset of English that can be unambiguously translated into first-order logic – is a knowledge representation language. To support automatic reasoning in ACE we have developed the Attempto Reasoner RACE (Reasoning in ACE). RACE proves that one ACE text is the logical consequence of another one, and gives a justification for the proof in ACE. Variations of the basic proof procedure permit query answering and consistency checking. Reasoning in RACE is supported by auxiliary first-order axioms and by evaluable functions. The current implementation of RACE is based on the model generator Satchmo.

Attempto controlled english: a knowledge representation language readable by humans and machines

Attempto Controlled English (ACE) is a knowledge representation language with an English syntax. Thus ACE can be used by anyone, even without being familiar with formal notations. The Attempto Parsing Engine translates ACE texts into discourse representation structures, a variant of first-order logic. Hence, ACE turns out to be a logic language equivalent to full first-order logic. The two views of ACE — natural language and logic language — complement each other, and render ACE both human- and machine-readable. This paper covers both views of ACE. In the first part we present the language ACE in a nutshell, and in the second part we give an overview of the discourse representation structures derived from ACE texts.

Schema-Based Transformations of Logic Programs

Transformation schemata are predefined abstract transformations of logic programs: input program schemata are transformed into output program schemata. Each transformation schema represents one transformation strategy, for example a particular sequence of applications of the unfold/fold rules, or the introduction of an accumulator data structure. The transformation of logic programs with the help of transformation schemata proceeds in three steps: abstraction of the programs to program schemata, selection of a transformation schema with these schemata as input and a suitable schema as output, and specialization of the output schema to the transformed program. Once the transformation schemata are available, user intervention is required only during the selection step. For standard transformation situations one can even envisage eliminating user interaction altogether by heuristics.

Writing clinical practice guidelines in controlled natural language

Clinicians could benefit from decision support systems incorporating the knowledge contained in clinical practice guidelines. However, the unstructured form of these guidelines makes them unsuitable for formal representation. To address this challenge we translated a complete set of pediatric guideline recommendations into Attempto Controlled English (ACE). One experienced pediatrician, one physician and a knowledge engineer assessed that a suitably extended version of ACE can accurately and naturally represent the clinical concepts and the proposed actions of the guidelines. Currently, we are developing a systematic and replicable approach to authoring guideline recommendations in ACE.