The logic we are mainly occupied with here is first-order logic (sometimes called first order predicate calculus (with functional terms and identity)). A case can be made that it is the main, or the one true, logic. Sowa writes:
2013
To learn about the Uniqueness quantifier (a part of identity), and to be introduced to definite descriptions.
Uniqueness is central in mathematics, and definite descriptions is a core area in philosophical logic.
To learn about functional terms and two new Rules of Inference II (Identity Introduction) and IE (Identity Elimination).
Reasoning with identity is vital for mathematics, philosophy, and many other areas.
To start to learn about identities, the semantics of identities, and typical expressions in English that might use identities.
Reasoning with identity is vital for mathematics, philosophy, and many other areas.
Welcome!
The tutorials presented here look at some topics in logic to the level of intermediate to advanced Predicate Calculus. They build on the Tutorials of Easy Deriver which provided the introductory material to Propositional and Predicate Calculus.
The program, widgets, or Notes, should be accompanied by a suitable textbook, such as:
These Gentzen Notes were brought in to the Content Management System from earlier Notes which were outside. The earlier Notes can be found at http://softoption.us/test/easyDeriver/tutorials/index.html
2013
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 ∼ ∧ ∨ ⊃ ≡ ∀ ∃ ∴ (or use the palette to produce them)
4/24/06
4/24/06
4/24/06