CAJ | 학술논문

把赋值语句看作物理对象上的操作时,程序就呈现为物理对象上的操作构成的表达式(简称O表达式).给出了定义O表达式语法的BNF公式,并用公理规定O表达式的语义.主动式的O表达式以计算最终结果为目的,因而相关公理给出的是施行表达式中操作以后的变量与施行之前变量之间的准确依赖关系.反应式O表达式要对外来需求作反应.描述反应的公理规定如何反应.有关通讯的公理要求正确的信息被正确的接受者收到.共享变量公理则给出有关共享变量的性质判断.例子用于说明异步顺序O表达式的性质是如何分析的.
파부치어구간작물리대상상적조작시,정서취정현위물리대상상적조작구성적표체식(간칭O표체식).급출료정의O표체식어법적BNF공식,병용공리규정O표체식적어의.주동식적O표체식이계산최종결과위목적,인이상관공리급출적시시행표체식중조작이후적변량여시행지전변량지간적준학의뢰관계.반응식O표체식요대외래수구작반응.묘술반응적공리규정여하반응.유관통신적공리요구정학적신식피정학적접수자수도.공향변량공리칙급출유관공향변량적성질판단.례자용우설명이보순서O표체식적성질시여하분석적.
A program turns out to be an expression of operations on physical objects (operation expression or O_expression for short) when assignments are treated as operations on physical objects. BNF formulas are given to define O expression syntax while axioms are proposed as semantics of O_expressions. An active O_expression computes some ultimate results. As such, an axiom for active O_expressions defines how a variable after the application of operations in an O_expression is precisely related to variables before the application. A reactive O_expression responses to requests from outside. An axiom, describing responses to requests, tells how a response should be made. Axioms on communications make sure that the right messages to be received by the right receivers while axioms about shared variables depict properties concerning shared variables. Examples are given to show how to analyze properties of asynchronous sequential O_expressions.