Let s be any positive constant, let (V,+,.) be any real inner product space and let V s ={ v ∈ V :| v |<s}. An Einstein gyrovector space (V s, ⊕ ⊕ , ⊗ ⊗ ) is an Einstein gyrogroup (V s, ⊕ ⊕ ) with scalar multiplication given by r ⊗ ⊗ v = s tanh(r tanh (| v |/ s)) v /| v | where r is any real number, v ∈ V s, v ≠ 0 and r ⊗ ⊗ 0 = 0 with the notation v ⊗ ⊗ r = r ⊗ ⊗ v.