How does reductio ad absurdum try to establish a claim?

In logic, reductio ad absurdum (Latin for "reduction to absurdity") establishes a claim by demonstrating that its negation leads to a logically necessary contradiction or an absurd consequence.12

This method, often referred to as indirect proof or reductio ad impossibile, functions through the following process:

• Assumption: You begin by assuming the opposite of the proposition you intend to prove.1
• Deduction: You then show that this assumption, when combined with other accepted or previously proven propositions, results in a logical contradiction.1
• Conclusion: Because the assumption leads to an impossibility, it must be false, thereby establishing that the original claim is true.12

While the term is sometimes used in casual conversation to describe taking an idea to an extreme, in formal logic, it serves as a rigorous tool for validating propositions by showing that their denial is untenable.12