1. Knowledge based reasoning uses logic and facts stored in a knowledge base to draw conclusions. The knowledge base represents information about the world that an AI system can use to solve problems. 2. A knowledge based agent is an AI system that maintains an internal state of knowledge in its knowledge base, reasons over that knowledge using inference rules, updates its knowledge base after observing new information, and takes actions. 3. A knowledge based agent's architecture includes a knowledge base to store facts, an inference system to apply logical rules to deduce new information and update the knowledge base, and the ability to perceive information, reason over its knowledge, and perform actions.

1. Topic To Be Covered:
I. Knowledge Based Reasoning
II. Knowledge Based Agents
Jagdamba Education Society's
SND College of Engineering & Research Centre
Department of Computer Engineering
SUBJECT: Artificial Intelligence & Robotics
Lecture No-1(UNIT-03)
Logic & Reasoning
Prof.Dhakane Vikas N

2. Knowledge Based Reasoning
What is Logic & Reasoning In AI?
 The main difference between logic and reason is that logic is basic facts or
knowledge about our world. For example, logic says that the “Throwing
stone will fall”. (Obviously, because of gravity!).
 Logic is the key behind any knowledge. It allows a person to filter the
necessary information from the bulk and draw a conclusion. In artificial
intelligence, the representation of knowledge is done via logics
 Reasoning is subject to personal opinion(Personal Thought
Process), whereas logic is an actual science that follows clearly
defined rules and tests for critical thinking.

3. Knowledge Based Reasoning
What is Knowledge Based Reasoning???
 Knowledge Base is a set of representation of Facts/Information about the
surrounding environment(Real World)
 Knowledge representation and reasoning (KR², KR&R) is the field of
artificial intelligence (AI) dedicated to representing information about the
world in a form that a computer system(Or AI Agent) can utilize to solve
complex tasks such as diagnosing a medical condition or having a dialog
in a natural language or Solving various real world Problems. Etc.
 Knowledge representation incorporates findings from psychology about
how humans solve problems and represent knowledge in order to design
formalisms that will make complex systems easier to design and build.

4. What is Knowledge Based Agents In AI?
What is Knowledge Based Agents In AI?
 Knowledge is the basic element for a human brain to know and
understand the things logically. When a person becomes knowledgeable
about something, he is able to do that thing in a better way.
 In AI, the agents which copy such an element of human beings are known
as knowledge-based agents.
 An intelligent agent needs knowledge about the real world for taking
decisions and reasoning to act efficiently.

5. What is Knowledge Based Agents In AI?
What is Knowledge Based Agents In AI?
 Knowledge-based agents are those agents who have the capability of
maintaining an internal state of knowledge, reason over that knowledge,
update their knowledge after observations and take actions.
 These agents can represent the world with some formal representation
and act intelligently.
Knowledge-based agents are composed of two main parts:
 Knowledge-base and
 Inference system.

6. The architecture of knowledge-based agent:
The architecture of
knowledge-based agent:
 The diagram is representing a
generalized architecture for a
knowledge-based agent.
 The knowledge-based agent (KBA)
take input from the environment by
perceiving the environment.
 The input is taken by the inference
engine of the agent and which also
communicate with KB to decide as
per the knowledge store in KB.
 The learning element of KBA
regularly updates the KB by
learning new knowledge.

7. The architecture of knowledge-based agent:
The architecture of
knowledge-based agent:
 Knowledge base: Knowledge-
base is a central component of
a knowledge-based agent, it is
also known as KB.
 It is a collection of sentences
(here 'sentence' is a technical
term and it is not identical to
sentence in English).
 These sentences are
expressed in a language
which is called a knowledge
representation language. The
Knowledge-base of KBA
stores fact about the world.

8. The architecture of knowledge-based agent:
The architecture of
knowledge-based agent:
Why use a knowledge base?
 Knowledge-base is required
for updating knowledge for
an agent to learn with
experiences and take action
as per the knowledge.

9. The architecture of knowledge-based agent:
Inference system
 A program’s protocol for
navigating through the rules and
data in a knowledge system in
order to solve the problem.
 Inference means deriving new
sentences from old.
 Inference system allows us to add a
new sentence to the knowledge
base.
 Inference system applies logical
rules to the KB to deduce new
information.

10. The architecture of knowledge-based agent:
Inference system
 Inference system generates new
facts so that an agent can update
the KB.
 An inference system works mainly
in two rules which are given as:
Forward chaining
Backward chaining

11. The architecture of knowledge-based agent:
Operations Performed by KBA
 Following are three operations
which are performed by KBA in
order to show the intelligent
behavior:
 TELL: This operation tells the
knowledge base what it perceives
from the environment.
 ASK: This operation asks the
knowledge base what action it
should perform.
 Perform: It performs the selected
action.