Logical System

## Review of material presented thus far

Review of new material

There are the truth-tables for the connectives...

Negation

F ∼F True False False True

Conjunction

F G (F∧G) True True True True False False False True False False False False

Disjunction

F G (F∨G) True True True True False True False True True False False False

Conditional

F G (F⊃G) True True True True False False False True True False False True

Biconditional

F G (F≡G) True True True True False False False True False False False True

There is the symbolization of arguments...

To symbolize an entire argument, we symbolize each of the propositions composing it, putting commas between the premises and a '∴' between the premises and the conclusion. Conventions adopted between symbols and atomic propositions are used uniformly throughout an entire argument.

There is the search for a counter-example...

Drawing up a 'long' truth-table... Or use the black art of transferring truth-values inward... Perhaps also using the 'satisfiability' of the set of formulas which has in it the premises and the negation of the conclusion.