## Tutorial 8: Reductio ad Absurdum

2013

### Skills to be acquired:

Learning reductio proof, both as plain Negation Introduction and via (double) Negation Elimination (to prove some formulas that do not have negation as their main connective).

### Reading

Bergmann[2004] *The Logic Book Section* 5.1 and 5.4

### The Tutorial:

Reductio ad Absurdum is the second of the classical forms of inference.