There are several ways to improve the computational complexity of this procedure. The first one consists in observing that if t ∈ 3 is a valid translation, then so is k × t + o where k ∈ and o ∈ 3 . This allows to minimise the volume of the new cell A (t) thanks to algebraic considerations. Let's illustrate this point in two dimensions for simplicity, although it can be generalised to any number of dimensions.