Logic Midterm 1 Flashcards
What is an argument
A series of sentences intended to support a particular conclusion
What are premises
Any statement that makes a claim about the way the world is and can be proven true or false
What is validity
An argument is valid iff there is no case where all the premises are true and the conclusion is false conclusion is false. {If the conclusion if false then argument is automatically valid)- another way to phrase would be the conclusion is a consequent of the premises
What is soundness
An argument is sound when its valid and has all true premises
What is a conclusion
The final sentence in an atgument
Consequence
A is a consequence of B iff there is no case where all of B are true and A is false
What does logical validity have
1.) the conclusion cannot be false while the premises are true
2.) the form/structure of the argument guarantees 1
Metavariable
A is a symbol in augmented English which we use to talk about expressions of TFL
Scope
The scope of connective is the sentence for which it is the main logical operator
Tautology
A is a tautology iff it is true on every valuation
Contradiction
Iff it is false on every valuation
Equivalent
iff they have the same truth value on every valuation
Jointly satisfiable
iff there if some valuation on which both are true
Entailment
A entails B iff every valuation that makes A true also makes B true
