An open extensible tool environment for Event-B

Abstract. We consider modelling indispensable for the development of complex systems. Modelling must be carried out in a formal notation to reason and make meaningful conjectures about a model. But formal modelling of complex systems is a difficult task. Even when theorem provers improve further and get more powerful, modelling will remain difficult. The reason for this that modelling is an exploratory activity that requires ingenuity in order to arrive at a meaningful model. We are aware that automated theorem provers can discharge most of the onerous trivial proof obligations that appear when modelling systems. In this article we present a modelling tool that seamlessly integrates modelling and proving similar to what is offered today in modern integrated development environments for programming. The tool is extensible and configurable so that it can be adapted more easily to different application domains and development methods.

An Open Extensible Tool Environment for Event-B

Abstract. We consider modelling indispensable for the development of complex systems. Modelling must be carried out in a formal notation to reason and make meaningful conjectures about a model. But formal modelling of complex systems is a difficult task. Even when theorem provers improve further and get more powerful, modelling will remain difficult. The reason for this that modelling is an exploratory activity that requires ingenuity in order to arrive at a meaningful model. We are aware that automated theorem provers can discharge most of the onerous trivial proof obligations that appear when modelling systems. In this article we present a modelling tool that seamlessly integrates modelling and proving similar to what is offered today in modern integrated development environments for programming. The tool is extensible and configurable so that it can be adapted more easily to different application domains and development methods.

Passiflora edulis Sims: the correct taxonomic way to cite the yellow passion fruit (and of others colors) Passiflora edulis Sims: a maneira taxonômica correta de referir-se ao maracujá-amarelo (e aos de outras cores)

Passiflora edulis, the passion fruit native from Brazil, has several common names (such as sour passion fruit, yellow passion fruit, black passion fruit, and purple passion fruit), and presents a wide variability with the different rind colors of its fruits, which are very easy to notice. However, in 1932, Otto Degener suggested that the yellow passion fruit had its origin in Australia through breeding, calling it P. edulis forma flavicarpa, and that it could be distinguished by the color of the fruit, the deeper shade of purple of the corona, and the presence of glands on the sepals. These distinctions do not support themselves, for the glands are common to the species (although they may be absent), and the corona has a wide range of colors, regardless of the color of the fruit. A more critical ingredient is the fact that the external coloration of the fruit is a character of complex inheritance and is not dominant, thus displaying a number of intermediate colors, making it difficult to identify the extreme colors. For the correct scientific naming of agricultural plants, the International Code of Botanical Nomenclature must be used in conjunction with the International Code of Nomenclature for Cultivated Plants, with the selections with significant agronomic characteristics recognized and named cultivars. In accordance with the international convention promoted by the UPOV, of which Brazil is a signatory, several colors (light yellow, yellow, orange yellow, pink red, red, red purple, green purple, purple, and dark purple) can be recognized in order to adequately characterize passion fruit cultivars within the species P. edulis. At taxonomic level, Passiflora edulis Sims must be used for any plant and color of sour passion fruits, in combination with a cultivar name for the selected materials.<br>Passiflora edulis, o maracujá é nativo do Brasil, apresenta vários nomes populares (tais como maracujá-azedo, maracujá-amarelo, maracujá-preto e maracujá-roxo) e grande variabilidade, sendo que diferentes cores da casca do fruto são facilmente observadas. Entretanto, em 1932, Otto Degener sugeriu que o maracujá-amarelo tenha originado através de melhoramento genético, na Austrália, denominando-o como P. edulis forma flavicarpa, e poderia ser reconhecido pela cor do fruto, pela porção colorida da corona, maior e de um arroxeado mais escuro, e pela presença de glândulas nas sépalas. Essa distinção não se sustenta, pois essas glândulas são comuns na espécie (embora possam estar ausentes), e a corona tem grande variação de cores, independentemente da cor do fruto. Ainda mais crítico é o fato de que a coloração externa do fruto é um caráter de herança complexa e não tem dominância, existindo, por isso, várias cores intermediárias e dificuldades para reconhecer quais as cores extremas. Para a correta denominação científica das plantas agrícolas, devem ser utilizados, simultaneamente, o Código Internacional de Nomenclatura Botânica e o Código Internacional de Nomenclatura de Plantas Cultivadas, sendo que seleções com características agronômicas importantes devem ser reconhecidas e denominadas como cultivares. De acordo com a convenção internacional promovida pela UPOV, da qual o Brasil é signatário, várias cores (amarelo-pálido, amarelo, amarelo-alaranjado, vermelho-rosado, vermelho, roxo-avermelhado, roxo-esverdeado, roxo e roxo-escuro) podem ser reconhecidas para a adequada caracterização das cultivares de maracujá, dentro da espécie Passiflora edulis. Ao nível taxonômico, portanto, correta, prática e simplesmente, deve-se utilizar Passiflora edulis Sims, para toda e qualquer planta e cor de fruto do maracujá-azedo, associando-se a elas um nome de cultivar para os materiais selecionados