derivations

Tutorial 7: Conditional Proof

Logical System

6/1/09 10 Software

Skills to be acquired:

Learning conditional proof.

Reading

Bergmann[2008] The Logic Book Section 5.1 and 5.4

The Tutorial:

The five remaining core sentential rules of inference are slightly more difficult than the ones that we have met before. They are slightly more difficult in that they require you to make new assumptions, and the correct new assumptions at that. However they follow a similar pattern to each other so mastery of one should lead to mastery of the others.

Tutorial 6: What is a derivation and what does it prove? How experts do derivations.

Topic
Logical System

5/29/09 10Software

Skills to be acquired in this tutorial:

a) Understanding the nature of derivation. b) Learning elementary Tactics.

Why this is useful:

Tactics will help you to do derivations.

Reading

Bergmann[2008] The Logic Book Section 5.1 and 5.4.

The Tutorial:

a)

A derivation or proof consists of a finite list of lines.

Tutorial 5: Valid arguments, searching for a proof

Logical System

5/18/09 10Software

Skills to be acquired in this tutorial:

Proving an argument to be valid by displaying a derivation. Simple sentential derivations using some of the Rules of Inference.

Reading

Bergmann[2004] The Logic Book Section 5.1.

The Tutorial:

If you suspect that an symbolized argument might be valid, you should attempt to give a derivation of it.

A derivation is a proof of validity.

Try your own derivations

Topic
Logical System

Roll your own derivations

6/21/07 10 Software

You may have derivations of your own that you wish to try. Just type, paste, or drag and drop, them into the panel, select your derivation, and click 'Start from selection'.

[Often copy-and-paste won't work directly from a Web Page; however, usually drag-and-drop will work!]

You will need to use the correct logical symbols. Here they are

F ∴ F . G ∼ ∧ ∨ ⊃ ≡ ∃ ∴

Try your own derivations

Logical System
12/28/20

Roll your own derivations

You may have derivations of your own that you wish to try. Just type, paste, or drag and drop, them into the panel, select your derivation, and click 'Start from selection'.

[Often copy-and-paste won't work directly from a Web Page; however, usually drag-and-drop will work!]

You will need to use the correct logical symbols. Here they are

F ∴ F ∧ G ∼ ∧ ∨ ⊃ ≡ ∀ ∃ ∴