Iṣu-gati

The arrow flies straight: the next body forms on the row the soul is already on, so it goes there in one samaya and is never without intake. This is the passage of the freed soul too, ṛju-gati, which is why the atlas draws that one separately - it is the same shape with no return.

On the lattice the path is drawn as the bhāṣya names it; the other three are beside it, so the four shapes can be read as one rule: a bend is a samaya, and a samaya on a bend takes nothing in.