SEPTIMUS It will go to infinity or zero, or nonsense
THOMASINA No, if you set apart the minus roots they square back to sense

Thomasina explains her theory to Septimus in Scene Seven. It is by this quote that the audience is sure Thomasina knows exactly what she is doing, she understands that sense will eventually arise from the disorder she has created with her equations. The "rabbit equation" Thomasina doesn't have time to extend is an iterated algorithm, a process of equations that describe a rabbit. Thomasina's equation cannot be completed without the aid of a computer to create the final fractal image, but it is clear she can somehow know the end result and picture her algorithm will create. Thomasina understands the eventual predictability of her algorithm and the eventual way her equation will "square back to sense."