Nitpicky comment / edit request: The circle inversion figure was quite confusing to me. Perhaps add a note to it saying that solid green maps onto solid blue, red maps onto itself, and dotted green maps onto dotted blue. (Rather than colours mapping to each other, which is what I intuitively expected.)
Nitpicky comment / edit request: The circle inversion figure was quite confusing to me. Perhaps add a note to it saying that solid green maps onto solid blue, red maps onto itself, and dotted green maps onto dotted blue. (Rather than colours mapping to each other, which is what I intuitively expected.)