Replacement and substitution, Computer Engineering

Replacement and substitution:

However, equivalences allow us to change one sentence with another without affecting the meaning, it means we know already that replacing one side of an equivalence into the other will have no effect so whatever on the semantics: but it will still be true for the same models. Just assume there we have a sentence S with a sub expression A that we write like S[A]. But there if we know A≡B so we can be sure the semantics of S is unaffected because we replace A with B, i.e. S[A] ≡S[B]. 

However, there we can also use A ≡B to replace any sub expression of S that is an instance of A. But there point to be remember that an instance of a propositional expression A is a 'copy' of A when some of the propositions of have been consistently replaced by original  sub expressions, e.g. to every P has been replaced by ¬Q. So than we call this replacement a substitution, and a mapping from propositions to expressions. Through applying a substitution U to a sentence S,  we find a new sentence S.U that is an instance of S. There always Ii is easy to show that if there A ≡B so A.U ≡B.U just for any substitution U, that is. an instance of an equivalence is as well an equivalence. Thus, an equivalence A ≡B allows us to change a sentence S[A'] to a logically and fundamentally equivalent one S[B'] but if we have substitution U like that A' = A.U and B' = B.U.

Posted Date: 1/11/2013 5:32:22 AM | Location : United States







Related Discussions:- Replacement and substitution, Assignment Help, Ask Question on Replacement and substitution, Get Answer, Expert's Help, Replacement and substitution Discussions

Write discussion on Replacement and substitution
Your posts are moderated
Related Questions
Register-to-Register Architecture : In this organization, results and operands are accessed not directly from the main memory by the scalar or vector registers. The vectors which a

Q. What do you mean by Shared Memory? In shared memory scheme more focus is on controlling parallelism instead of data parallelism. In this model numerous processes run indepen

Data Stream and Instruction Stream The term 'stream' refers to an order or flow of either data operated or instructions on by the computer. In the complete chain of instructi


What is object orientation? Object orientation means that we classify software as a collection of discrete objects that incorporate with together DS and behaviour. Four aspe


i need help with an octave program

What is branch instruction? As a result of branch instruction is a type of instruction which loads a latest values into the program counter.

What are the differences between ASP and ASP .Net ?    1. ASP: Code is Interpreted ASP.NET: Code is Compiled 2. ASP: Business Logic and Presentation Logic are in a one

how create database design for pharmacy by diagram and query