Lexical and dynamic scoping are the two primary approaches to variable binding in functional programming languages. While medieval Lisp dialects commonly featured dynamic scoping, most languages today emphasize lexical scoping. This is a sensible choice: lexical scoping enables local reasoning about programs at the source code level. Nonetheless, dynamic variables are more appropriate for certa...

AIMS To assess the contribution of the four major operational variables in the radial keratotomy operation (RK) to the correction of myopic eyes. To study the deformation of the cornea after the operation and provide some valuable references for clinical practice. METHODS The expression of the correction ratio has been deduced, which can be directly represent as the deformation ratio of the c...

Goossens defined structural operational semantics for a subset of VHDL-87 and proved that the parallelism present in VHDL is benign. We extend this work to include VHDL-93 features such as shared variables and postponed processes that change the underlying semantic model. In the presence of shared variables, nondeterministic execution of VHDL-93 processes destroys the unique meaning property. W...

In this paper we consider synchronous parallel programs P that are composed by sequential randomized processes S Sk which communicate via shared variables First we give an operational semantics for the sequential components Si on the basis of a transition relation de ned in the classical SOS style a la Plotkin Plo which we use to specify the behaviour of P by a Markov chain whose transitions st...

In this article we present a true-concurrent operational semantics of a Pascal-like language with a parallel operator and shared memory. This semantics is based on a higher-dimensional transition system that is able to model the asyn-chronous execution of concurrent operations. We show how it can be usefully abstracted to nite automata via abstract interpretation using folding of states and app...

The Behavior Tree notation is used as part of a framework for developing complex computer systems. The framework is designed to simplify the process of constructing a formal specification of a system from its informal functional requirements. To give a meaning to Behavior Trees, this paper describes a lower-level language called Behavior Tree Process Algebra (BTPA) and its operational semantics...

In an attempt to define a generic way to include human factors in a simulation of military operations HFM 128 suggested to break the causal chain between human factors as input and operational outcome into three components: a) human factors science based models to calculate state variables of the human, b) Performance Shaping Functions (PSF) to quantify the effect of states on individual perfor...