Symbolic Logic

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Questions 1 - 10
1

Identify the complex sentence of the following statement:

Sally has a cake and she sells it to her friend Betty.

Explanation

First-order logic statements can be described in complex sentences by using logic symbols.

Recall the following logic symbols.

means "not"

means "implies"

means "or"

means "and"

means "equivalent"

For this particular problem the starting sentence is,

"Sally has a cake and she sells it to her friend Betty."

First, identify the first-order statements and write them in symbolic form. This particular sentence has two first-order statements.

Statement 1: Sally has a cake

Statement 2: Sally sells her cake to her friend Betty.

To combine these statements into one complex sentence, it needs to be understood that once Sally sells her cake she no longer has it therefore, the statement becomes:

2

Which of the following symbols is a "quantifier"?

Explanation

Symbolic logic describes English statements using mathematical symbols. These mathematical symbols can be categorized into five areas.

I. Predicates: ,

II. Terms: Terms are the variables that represents the objects and constants of a statement.

III. Quantifiers: ,

IV. Punctuation: (,)

V. Connectives : , , , , , ,

This particular question asks to identify the "quantifier".

Since there are only two symbols that are categorized as "quantifiers", and ,and the "exists" symbol is the only one present in the answer choices, that is the correct answer.

3

Which of the following statements is part of the definition for sentential logic?

If and are formulas then is a formula as well.

Every lower case letter is a formula.

Anything and everything can be considered a formula.

If is a formula then so is .

If is a formula then so is .

Explanation

It is important to recall that sentential logic has a very specific definition that outlines and describes different formulas.

There are seven different statement criteria when discussing sentential logic and they are as follows.

I. If is a formula then is a formula as well.

II. If and are formulas then is a formula as well.

III. If and are formulas then is a formula as well.

IV. If and are formulas then is a formula as well.

V. If and are formulas then is a formula as well.

VI. All upper case letters are formulas

VII. Nothing else is a formula.

Looking at the possible answer selections only IV is part of the sentential logic definition thus, "If and are formulas then is a formula as well." is in the definition.

4

Looking at the following truth table, find the missing operator if

.

Explanation

To help solve for the missing operator in this truth table, first recall the different operators and there meanings.

In truth tables when the "or" operator is used translates to, either and (the constants) being true. When the "and" operator is used that means that for the result to hold true both the constants must be true. The "not" operator negates the answer. The "implies" that the first constant results in the second constant . Lastly, the "equivalency" operator signifies that both constants are the same.

Looking at the truth table,

and result in a true statement whenever the first constant is the same as the second constant. Therefore, the missing operator is "implies".

In mathematical terms the missing operator is .

5

Which of the following symbols is a "quantifier"?

Explanation

Symbolic logic describes English statements using mathematical symbols. These mathematical symbols can be categorized into five areas.

I. Predicates: ,

II. Terms: Terms are the variables that represents the objects and constants of a statement.

III. Quantifiers: ,

IV. Punctuation: (,)

V. Connectives : , , , , , ,

This particular question asks to identify the "quantifier".

Since there are only two symbols that are categorized as "quantifiers", and ,and the "exists" symbol is the only one present in the answer choices, that is the correct answer.

6

Identify the complex sentence of the following statement:

Sally has a cake and she sells it to her friend Betty.

Explanation

First-order logic statements can be described in complex sentences by using logic symbols.

Recall the following logic symbols.

means "not"

means "implies"

means "or"

means "and"

means "equivalent"

For this particular problem the starting sentence is,

"Sally has a cake and she sells it to her friend Betty."

First, identify the first-order statements and write them in symbolic form. This particular sentence has two first-order statements.

Statement 1: Sally has a cake

Statement 2: Sally sells her cake to her friend Betty.

To combine these statements into one complex sentence, it needs to be understood that once Sally sells her cake she no longer has it therefore, the statement becomes:

7

Which of the following statements is part of the definition for sentential logic?

If and are formulas then is a formula as well.

Every lower case letter is a formula.

Anything and everything can be considered a formula.

If is a formula then so is .

If is a formula then so is .

Explanation

It is important to recall that sentential logic has a very specific definition that outlines and describes different formulas.

There are seven different statement criteria when discussing sentential logic and they are as follows.

I. If is a formula then is a formula as well.

II. If and are formulas then is a formula as well.

III. If and are formulas then is a formula as well.

IV. If and are formulas then is a formula as well.

V. If and are formulas then is a formula as well.

VI. All upper case letters are formulas

VII. Nothing else is a formula.

Looking at the possible answer selections only IV is part of the sentential logic definition thus, "If and are formulas then is a formula as well." is in the definition.

8

Looking at the following truth table, find the missing operator if

.

Explanation

To help solve for the missing operator in this truth table, first recall the different operators and there meanings.

In truth tables when the "or" operator is used translates to, either and (the constants) being true. When the "and" operator is used that means that for the result to hold true both the constants must be true. The "not" operator negates the answer. The "implies" that the first constant results in the second constant . Lastly, the "equivalency" operator signifies that both constants are the same.

Looking at the truth table,

and result in a true statement whenever the first constant is the same as the second constant. Therefore, the missing operator is "implies".

In mathematical terms the missing operator is .

9

Which of the following statements is NOT a definition of sentential logic?

Only , , , and are formulas.

If is a formula then is a formula as well.

If and are formulas then is a formula as well.

If and are formulas then is a formula as well.

If and are formulas then is a formula as well.

Explanation

It is important to recall that sentential logic has a very specific definition that outlines and describes different formulas.

There are seven different statement criteria when discussing sentential logic and they are as follows.

I. If is a formula then is a formula as well.

II. If and are formulas then is a formula as well.

III. If and are formulas then is a formula as well.

IV. If and are formulas then is a formula as well.

V. If and are formulas then is a formula as well.

VI. All upper case letters are formulas

VII. Nothing else is a formula.

Looking at the possible answer selections, I, II, III, and IV are part of the sentential logic definition thus, "Only , , , and are formulas." is NOT in the definition. This can be verified by part VI in the definition which states that all upper case letters are formulas.

10

Looking at the following truth table, find the missing operator if

.

Explanation

To help solve for the missing operator in this truth table, first recall the different operators and there meanings.

In truth tables when the "or" operator is used translates to, either and (the constants) being true. When the "and" operator is used that means that for the result to hold true both the constants must be true. The "not" operator negates the answer. The "implies" that the first constant results in the second constant . Lastly, the "equivalency" operator signifies that both constants are the same.

Looking at the truth table,

and result in a true statement whenever one of the constants is true. Therefore, the missing operator is "or".

In mathematical terms the missing operator is .

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