A model processes a sequence of vectors ($\mathbf{v}_1, \mathbf{v}_2, \mathbf{v}_3, ...$) using a context window of size $n_c=7$. The set of vectors for the window is defined as ${\mathbf{v}_{i-n_c+1}, ..., \mathbf{v}_i}$. If the model is at the current position $i=4$, which specific vectors from the sequence are included in the context window? Justify your answer by showing the initial index calculation and explaining how the final set of vectors is determined.