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Definitions
Truth Tables
Dilemmas
Formal Proofs
Miscellany
100
It is the branch of formal deductive logic in which the basic unit of thought is the proposition.
What is propositional logic?
100
These are used to determine the truth value of compound propositions given the truth value of their component parts.
What are truth tables?
100
This is a valid dilemma which presents a valid choice between two conditionals?
What is a dilemma?
100
This is a valid argument form which can be used to justify steps in a proof.
What is a rule of inference?
100
A proposition that is always true due to its logical structure.
What is tautology?
200
It is another name for a statement.
What is a proposition?
200
This is when two propositions have identical truth values in a truth table.
What is logically equivalent?
200
This is another name for rejecting one of the conditionals in a conjunctive premise.
What is grasping the horns?
200
This is the only rule that allows you to introduce a new variable to the proof.
What is addition?
200
This is the author of the textbook "Intermediate Logic."
Who is James B. Nance?
300
It is a statement that has only one component part.
What is a simple proposition?
300
This is what the argument is if one sets the premises to true and the conclusion false and no contradiction occurs.
What is invalid.
300
This is another name for writing a counter-dilemma to defeat the dilemma.
What is rebutting the horns?
300
It is the end goal for every proof of validity.
What is deducing the conclusion from the premises?
300
This is a deductive argument that contains three terms, two premises and one conclusion.
What is a syllogism?
400
When a statement's truth value depends upon the truth values of its component parts.
What is truth functional?
400
Propositions are considered this when one assumes them all to be true and no contradiction occurs.
What is consistent?
400
This method for defeating the dilemma involves denying the disjunctive premise and providing a third alternative.
What is going between the horns?
400
These can represent very complicated compound propositions.
What are variables?
400
This is the name for a proposition used in a distinction.
What is disjunct?
500
It is a lowercase letter that represents any proposition.
What is a propositional variable?
500
It's the outcome that occurs after setting the propositions to opposite truth values and getting an unavoidable contradiction.
What is equivalence?
500
This type works like modus tollens.
What is a destructive dilemma?
500
These two rules are often overlooked in a formal proof of validity.
What are absorption and addition?
500
This is what is written at the end of a completed formal proof of validity (must give the full phrase spelled correctly).
What is "Quod erat demonstrandum?"