ABSTRACT
Defi nition 12.1 (Gyroellipses). Let (R2s, ⊕, ⊗) be an Einstein gyrovector plane, and let F1, F2 ∈ R2s be two distinct gyropoints. A gyroellipse is the locus of a gyropoint P ∈ R2s that moves in such a way that the gyrosum of its gyrodistances from F1 and F2 is a constant, a0 that is,
|| F1⊕P||⊕|| F2⊕P|| = a0. (12.1) The gyropoints F1 and F2 are called the gyrofoci of the gyroellipse.
