First-order logic (relevant)

Question 1

What does the FOL do?

Answer 1

Add to the language of TFL

Question 2

Names =

Answer 2

Lowercase letters

Question 3

Predicates are…

Answer 3

Not complete sentences by themselves, usually say something about the object

Question 4

Predicates =

Answer 4

Uppercase letter followed by ‘x,’ e.g. Fx, Gx

Question 5

Quantifiers

Answer 5

The universal quantifier, the existential quantifier

Question 6

The universal quantifier

Answer 6

‘Upside down A’x

Question 7

The existential quantifier

Answer 7

‘Backwards E’x

Question 8

What does the universal quantifier read as?

Answer 8

For all x/for every x

Question 9

What does the existential quantifier read as?

Answer 9

For some x/for at least one x

Question 10

What are predicates usually?

Answer 10

Properties of individuals, they combine with singular terms to make sentences

Question 11

If a predicate has one gap it is called…

Answer 11

A one place predicate

Question 12

How can we form two-place predicates?

Answer 12

Removing two singular terms and using two different variables (‘x’ or ‘y’) to represent the two gaps

Question 13

What are two-place predicates known as?

Answer 13

Relations

Question 14

Are the terms: nothing/everybody/someone/something names?

Answer 14

No, they aren’t names/singular terms so are expressed by quantifiers

Question 15

What are domains?

Answer 15

The set of things that we are talking about. Quantifiers range over the domain

Question 16

What must the domain contain?

Answer 16

One thing, each name must pick out exactly one thing in the domain

Question 17

The order of quantifiers

Answer 17

Matters, changing the order changes the sentence