Answer :
To analyze the possible sets of letters obtained by drawing lines through the bottom-left point and at least one other bold point in the given \(3 \times 3\) grid, we need to understand the patterns formed by the lines in such a grid.
Firstly, let's observe the given grid:
\[
\begin{array}{|c|c|c|c|c|}
\hline
\epsilon & H & 1 & \mathbf{c} & \mathrm{a} \\
\hline
0 & \epsilon & F & \mathbf{b} & E \\
\hline
\mathbf{A} & a & \mathrm{c} & \mathbf{A} & n \\
\hline
c & u & 1 & c & \bar{n} \\
\hline
D & E & E & D & = \\
\hline
& \mathbf{n} & C & \mathbf{A} & B \\
\hline
\end{array}
\]
Here, the bold letters represent the points of interest for drawing lines.
Now, let's analyze the possible sets of letters obtained by drawing lines:
1. **Set 1: \( \{A, B, C\} \)**
This set is obtained by drawing a line through points A, B, and C.
2. **Set 2: \( \{A, F, H\} \)**
This set is obtained by drawing a line through points A, F, and H.
3. **Set 3: \( \{A, E, D\} \)**
This set is obtained by drawing a line through points A, E, and D.
4. **Set 4: \( \{A, n, C\} \)**
This set is obtained by drawing a line through points A, n, and C.
In the \(3 \times 3\) grid, we observe that no line passes through more than 3 different letters. Additionally, each set of letters can only be obtained by one unique configuration of lines.
Now, let's predict what would happen with larger grids:
- **Repeated \(5 \times 5\) Grid**:
In a \(5 \times 5\) grid, the same patterns would apply, and it's likely that we would get different sets of letters, possibly with a slightly increased number of possible sets due to the larger grid size.
- **Repeated \(6 \times 6\) Grid**:
Similarly, the patterns observed in the \(3 \times 3\) grid would still hold, but there might be more variations in the sets of letters due to the increased grid size.
- **Repeated \(7 \times 7\) Grid**:
The patterns are likely to continue, but the number of possible sets may increase further due to the larger grid size, leading to more variations in the sets of letters.
The predictions are based on the observation that the patterns formed by the lines in the grid are likely to persist in larger grids, leading to similar but potentially more varied sets of letters. Each set of letters would still be determined by the unique configurations of lines passing through the bold points.