# Unit 2 Basic Concepts

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The flashcards below were created by user ceilingmoth on FreezingBlue Flashcards.

1. Simple statement
A statement is simple if and only if it does not contain any other statement as a component
2. Compound statement
A statement is compound if and only if it contains at least one simple statement as a component
3. Well formed formula (WFF)
and 4 components
A well-formed formula is a syntactically correct arrangement of symbols

• a. upper case letters
• b. operators
• c. logical punctuation marks
• d. logical variables
4. Main operator
the main operator is the operator that determines the overall structure of a well-formed formula
5. Subformula
a subformula is any well-formed part of a well-formed formula
6. tautology statement form
a statement form is a tautology if an only if it is true for every substitution instance
7. tautology statement
a statement is a tautology if and only if it is a substitution instance of a tautologous form
logical falsity, necessary falsity
a statement form is a self-contradiction if and only if it is false for every substitution instance
a statement is a self-contradiction if and only if it is a substitution instance of a self-contradictory form
11. tautology
logical truth, necessary truth
12. contingency statement form
a statement form is a contingency if and only if it is true for at least one substitution instance and false for at least one substitution instance
13. contingency statement
a statement is a contingency if and only if it is a substitution instance of a contingent form
14. logical equivalence statement forms
two statement forms are logically equivalent if and only if the two final columns of their joint truth table are identical (true/true or false/false)
15. logical equivalence statements
two statements are logically equivalent if and only if they are substitution instances of logically equivalent forms
16. inconsistency statement forms
two statement forms are inconsistent if and only if there is no line in the final columns of their joint truth table on which both forms have the T truth value
17. inconsistency statements
two statements are inconsistent if and only if they are substitution instances of inconsistent forms
18. consistency statement forms
two statement forms are consistent if and only if there is at least one line in the final columns of their joint truth table on which both forms have the T truth value
19. consistency statements
two statements are consistent if and only if they are substitution instances of consistent forms
20. logical implication statement forms
one statement form logically implies another form if and only if there is no line in the final columns of their joint truth table on which the firm form has the T truth value, while the second had the F truth value
21. logical implication statements
one statement logically implied another statement if and only if they are substitution instances  of implicative forms

### Card Set Information

 Author: ceilingmoth ID: 309139 Filename: Unit 2 Basic Concepts Updated: 2015-10-06 22:07:18 Tags: logic Folders: logic Description: x Show Answers:

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