---
tag: FJN3XDRXAR
kind: concept
name: Conjunction introduction
aliases: [adjunction-rule-of-inference, conjunction-and-introduction]
sources:
  - wikipedia: en:6563@r1316809696
    locator: Conjunction introduction
    note: adopted
    mention: wikipedia://en/6563
    sections: [Summary]
same_as:
  wikidata: Q5161172
  wikipedia: Conjunction introduction
inventory: [HEENKMPV6F]
---

## Summary

**Conjunction introduction** (often abbreviated simply as **conjunction** and also called **and introduction** or **adjunction**) is a valid rule of inference of propositional logic. The rule makes it possible to introduce a [[conjunction|025YZN3VJW]] into a logical proof. It is the inference that if the [[proposition|0ZGC7ZESYN]] $P$ is true, and the proposition $Q$ is true, then the logical conjunction of the two propositions $P$ and $Q$ is true. For example, if it is true that "it is raining", and it is true that "the cat is inside", then it is true that "it is raining and the cat is inside". The rule can be stated: