# Definition:Proposition

From ProofWiki

## Definition

A **proposition** is a statement which is offered up for investigation as to its truth or falsehood.

Loosely, a **proposition** is a statement which is about to be proved (or disproved).

## Also defined as

Some sources, while appreciating the need under certain circumstances to do so, do not distinguish between the concept of a statement, as defined here on $\mathsf{Pr} \infty \mathsf{fWiki}$, and a **proposition**, using the terms interchangeably:

*"There are good reasons, which fortunately we do not need to go into, for avoiding the term 'proposition'. On the other hand, we shall, in the early sections of this book, be working with what is known as the*Propositional Calculus*. We shall use the terms 'statement' and 'proposition' interchangeably."*- D.J. O'Connor and Betty Powell:
*Elementary Logic*(1980): $\S 1.1$

- D.J. O'Connor and Betty Powell:

## Sources

- E.J. Lemmon:
*Beginning Logic*(1965)... (previous)... (next): $\S 1.1$: The Nature of Logic - Irving M. Copi:
*Symbolic Logic*(4th ed., 1973)... (previous)... (next): $1.2$: The Nature of Argument - T.S. Blyth:
*Set Theory and Abstract Algebra*(1975)... (previous)... (next): $\S 1$ - D.J. O'Connor and Betty Powell:
*Elementary Logic*(1980)... (previous)... (next): $\S \text{I}: 1$: The Logic of Statements $(1)$ - M. Ben-Ari:
*Mathematical Logic for Computer Science*(1st ed., 1993)... (previous)... (next): $\S 1.2$: Propositional and predicate calculus