Here I will finish the explanation of everything else that I was taught about natural deduction (even if we didn't use it very much). The quantifiers thing is really important, but more complex.

- 7.1 Rules about truth and false

- 7.2 Rules about quantifiers
- 7.2.1 What's that
- 7.2.2 Existential introduction
- 7.2.3 Existential elimination
- 7.2.4 Universal introduction
- 7.2.5 Universal elimination
- 7.2.6 Examples

- 7.3 Derived rules

Daniel Clemente Laboreo 2005-05-17