15 lines
		
	
	
	
		
			419 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			15 lines
		
	
	
	
		
			419 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
---
 | 
						|
categories:
 | 
						|
  - Logic
 | 
						|
tags: []
 | 
						|
---
 | 
						|
 | 
						|
# Negation Introduction
 | 
						|
 | 
						|
This is also known as _proof by contradiction_. You start with an assumption
 | 
						|
declared in a sub-proof. If you can derive a contradiction from this assumption
 | 
						|
(typically from the introduction of another proposition and its negation), then
 | 
						|
you are permitted to derive the negation of the auxiliary assumption in the main
 | 
						|
proof.
 | 
						|
 | 
						|

 |