Original
This idea originated from Robert Freud to earlier studies, and he provided a similar system for the flowchart. TEO Hall first published in 1969 [and then refined to other researchers.
hoare logic (also known as floyd-hoare logic ) is a form system developed by the British computer scientist Car Hoare, followed by Hoare and other researchers refined. It published in the 1969 papers "Computer Procedure Basis". The purpose of this system is to provide a set of logical rules to provide the correctness of computer programs using a strict proactive logic.
hoare recognizes the early contribution of Robert Floyd, and he provides a similar system for the flowchart.
Hall Trimethal Group
The center characteristics of Hall logic are Hoare Triple. This three-group describes how to perform the execution of the code changes the status of the calculation. The Hoare ternary group has the following form
here p and q is Askical and c is command . P is called Pre-condition and Q is called post-condition . As a result of the predicate logic. This ternary group is in intuition: as long as P is established in c , the Q is also established after execution. Note If the C is terminated, it is not there, so Q can be at all, it can be any statement. In fact, you can choose q to express c not terminated. In fact, this situation is called "Partial Correctness". If c is terminated and Q is true when terminating, the expression is referred to as "Total Correctness". The termination must be certified separately.
Hall logic provides a actions and reasoning rules for all constructs of simple ordered programming languages. In addition to the rules of the simple language in the HOARE paper, other language structure has also been developed by Hoare and many other researchers. Includes concurrent, procedures, goto statements, and pointers.
Ordinary programming
Command programming (English: imperative programming) is a programming model for the behavior required to describe the computer. Almost all computer hardware work is ordered; almost all computer hardware is designed to run the machine code, written in the style of the command. The higher-end command-programming language uses variables and more complex statements, but still comps from the same model. Cooking and a list of action, although non-computer programs, there is similar style with ordered: each step is instructions, tangible world control. Because of the basic concept of ordered, not only is more familiar, but it is easier to perform in hardware, so most of the programming languages are orders.