`A-B` is equal to

Options

A. `B-A`
B. `A uuB`
C. `A nnB`
D. `A-(AnnB)`

Answer

To find the set difference \( A - B \), we follow these steps:

### Step 1: Understand the Definition of Set Difference
The set difference \( A - B \) (also denoted as \( A \setminus B \)) is defined as the set of elements that are in set \( A \) but not in set \( B \).

### Step 2: Identify the Elements of Sets A and B
Let's assume we have two sets:
- Set \( A = \{ a_1, a_2, a_3, \ldots, a_n \} \)
- Set \( B = \{ b_1, b_2, b_3, \ldots, b_m \} \)

### Step 3: Determine the Elements in \( A \) that are not in \( B \)
To find \( A - B \), we need to look at each element in set \( A \) and check if it is present in set \( B \). If an element from \( A \) is not found in \( B \), it will be included in the resulting set \( A - B \).

### Step 4: Write the Resulting Set
The resulting set \( A - B \) will be:
\[ A - B = \{ x \in A \mid x \notin B \} \]

### Example
If we take:
- \( A = \{ 1, 2, 3, 4 \} \)
- \( B = \{ 3, 4, 5 \} \)

Then:
- \( A - B = \{ 1, 2 \} \) because 1 and 2 are in \( A \) but not in \( B \).

### Conclusion
Thus, \( A - B \) is the set of elements that belong to \( A \) but not to \( B \).

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