test_dptable_arrows

Step 1: single arrow from cell 0 to cell 1.

Step 2: two arrows targeting the same cell (cell 2).

Step 3: longer-range arrow from cell 0 to cell 4.

Step 4: reannotate – replace annotations on cell 4 with path arrow.

Same-row arrow: cell[0][0] to cell[0][1].

Same-column arrow: cell[0][0] to cell[1][0] (vertical).

Diagonal arrow: cell[0][0] to cell[1][1].

Multiple arrows to same 2D target: cell[2][2] from three sources.

Same-column long arrow: cell[0][3] to cell[3][3].

Reannotate in 2D: replace annotations on cell[2][2] with a single path arrow.