Generally, a proposition is a statement
, a sentence
that makes a claim
such as "This water tastes bad."
There are four kinds of propositions, labeled A, E, I, and O.
An 'A' proposition claims that "All A are P."
An 'E' proposition claims that "No A are P."
An 'I' proposition claims that "Some A are P."
An 'O' proposition claims that "Some A are not P."
Propositions are used in everyday language. A simple sentence can be a proposition. A proposition is labeled for the purpose of determining its validity
, its truthfulness
, against other statements in logical arguments when compared to other statements in that argument
"This water tastes bad" would be an example of an 'A' proposition, because the speaker is including all of 'this' water in his claim.