This document defines propositions and their classification in symbolic logic. A proposition is a statement that is either true or false, but not both. Propositions can be simple, which have the most basic sentence structure, or compound, which are the union of two or more simple propositions joined by connectors like "and" or "or". The document provides examples of simple and compound propositions and explains how to identify whether a statement is a proposition or not based on if it can be proven true or false.
2. 1.2 CLASSIFICATION OF PROPOSITIONS.
Logic is a reasoning method that does not accept conclusions,
except when they are inevitable. This can be achieved due to the
strict format in which each of the concepts is defined. Nothing
can be taken as given and dictionary definitions in some cases,
are not enough.
In common language, a sentence can be defined as ” a group of
words that declare, ask, commands, or exclaims something,
regularly containing a subject and predicate, starting with a
capital letter and ending in a period ”.
3. 1.2 CLASSIFICATION OF PROPOSITIONS.
However, in Symbolic Logic, a sentence has a very limited
definition, and it is called proposition.
Proposition is a sentence that is true or false, but not true and
false at the same time.
Pay close attention to the following examples and, if possible,
apply the definition of proposition.
Neil Armstrong walked on the moon.
𝟑 + 𝟐 = 𝟕 Donald Duck is the U.S. President.
4. 1.2 CLASSIFICATION OF PROPOSITIONS
In the previous examples, propositions were easily identified,
because telling if they were true or false was very obvious,
and it does not admit any doubt.
Check the following examples, tell if the given statement is a
proposition or not.
Go away!
𝟑𝟎 + 𝒙 = 𝟒𝟎 What are you doing?
5. 1.2 CLASSIFICATION OF PROPOSITIONS.
Therefore, if the statement can not be proven true or false, we
can say it is not a proposition.
CLASSIFICATION OF PROPOSITIONS.
Once the statement has been classified as a proposition, we
need to determine the type of proposition they are.
Basically, propositions can be classified in two categories:
Simple Propositions
Compound Propositions
6. 1.2 CLASSIFICATION OF PROPOSITIONS.
Simple Propositions are also known as atomic propositions,
because they have the most basic structure in the sentence
(atom). Some examples of simple propositions are.
𝑰𝒕′𝒔 𝒓𝒂𝒊𝒏𝒊𝒏𝒈.
𝑰𝒕′𝒔 𝒗𝒆𝒓𝒚 𝒉𝒐𝒕.
Compound propositions are the union of two or more simple
propositions joined by a connector such as and or or. They are
also known as molecular propositions. For example:
7. 1.2 CLASSIFICATION OF PROPOSITIONS.
𝑰𝒕′𝒔 𝒓𝒂𝒊𝒏𝒊𝒏𝒈 𝒂𝒏𝒅 𝒊𝒕′𝒔 𝒗𝒆𝒓𝒚 𝒉𝒐𝒕.
𝑰𝒕′𝒔 𝒓𝒂𝒊𝒏𝒊𝒏𝒈 𝒐𝒓 𝒊𝒕′𝒔 𝒗𝒆𝒓𝒚 𝒉𝒐𝒕.
The connectors and, or are not part of the propositions. They
were added to the simple propositions to create a compound
proposition.