Unification - artificial intelligence, Computer Engineering

Assignment Help:

Unification - Artificial intelligence:

We have said that the laws of inference for propositional logic detailed in the previous lecture can also be used in first-order logic. However, we have to clear that a little. One important distinction between propositional and first-order logic is that the latter has predicates with expressions as arguments. So, one explanation we have to form is that we may use the inference lawsas long as the predicates and Arguments match up. That's why, not only do we have to check for the right kinds of sentence before we may carry out a law of inference, we also need to check that the arguments do not prohibit the inference.

For instance, let it in our knowledge base, we have the these two statements:

Knows (john) -> hates(john, X)

Knows(john, marry)

and we need to use the Modus Ponens law to infer something latest. In this case, there is no difficulty, and we may infer that, because john hates everybody  he knows, and he knows Mary, then he should hate Mary, i.e., we may infer that hates(john, mary) is right.

However, let it instead that we had these two sentences:

knows(john,X) -> hates(john, X)

knows(jack, mary)

Here, the predicate names have not altered, but the arguments are handling us back from forming any deductive inference. In the first case above, we might allow the variable X to be instantiated to marry during the assumption, and the constant john before and after the assumption also matched without error. However, in the second case, although we might still instantiate X to marry, we could no longer match john and jack, because they are two dissimilar constants. So we cannot deduce anything for john (or anyone else) from the latter two statements.

The problem here arises from our incapability to make the arguments in knows(john, X) and the arguments in knows(jack, marry) match up. When we may make two predicates match up, we say that we have combined them, and we will look at an algorithm for unifying two predicates (if they can be combined) in this section. Remember that unification acts a part in the way Prolog searches for matches to queries.


Related Discussions:- Unification - artificial intelligence

C++, #question.constructors and destructors

#question.constructors and destructors

Define user space, Define user space? The system space is divided from ...

Define user space? The system space is divided from virtual address space in which the user application programs reside. The letter space is known as user space.

What is stack, Stack is a portion of RAM used for saving the content of Pro...

Stack is a portion of RAM used for saving the content of Program Counter and common purpose registers. LIFO stacks, also called as "push down" stacks, are the conceptually easi

Computer arcticture, what is the main goal of parallel processing

what is the main goal of parallel processing

Data structure in which an element is added, A data structure in which an e...

A data structure in which an element is added and detached only from one end, is known as Stack

What is a client in sap terminology, What is a client in SAP terminology? ...

What is a client in SAP terminology? A S/W component that uses the service (offered by a s/w component) is known as a Client.  At the similar time these clients may also be ser

Explain a multiprocessing operating system, Explain a multiprocessing opera...

Explain a multiprocessing operating system? A multiprocessing system is a computer hardware configuration which contains more than one independent processing unit. Multiprocess

What are disadvantages of eprom, What are disadvantages of EPROM? The c...

What are disadvantages of EPROM? The chip must be physically removed from the circuit for reprogramming and its whole contents are erased by the UV light.

Explain the need for user-defined functions, Explain the need for user-defi...

Explain the need for user-defined functions. The need for user-defined function: 1.  A programmer might be having a block of code that he has repeated forty times all over t

Where trunks lines are run between, Trunks are the lines that run between ...

Trunks are the lines that run between (A)  subscribers and exchange        (B) switching system and power plant (C)  Local Area Network                (D) switching syste

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd