From 5cbb93016e4b192d2a2d7be81014a55a33c9a8f9 Mon Sep 17 00:00:00 2001 From: Michael Orlitzky Date: Thu, 10 Oct 2019 09:26:08 -0400 Subject: [PATCH] eja: add another test for element inverses. --- mjo/eja/eja_element.py | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mjo/eja/eja_element.py b/mjo/eja/eja_element.py index c2f9fe6..5944c07 100644 --- a/mjo/eja/eja_element.py +++ b/mjo/eja/eja_element.py @@ -460,6 +460,17 @@ class FiniteDimensionalEuclideanJordanAlgebraElement(IndexedFreeModuleElement): ... ValueError: element is not invertible + Proposition II.2.3 in Faraut and Koranyi says that the inverse + of an element is the inverse of its left-multiplication operator + applied to the algebra's identity, when that inverse exists:: + + sage: set_random_seed() + sage: J = random_eja() + sage: x = J.random_element() + sage: (not x.operator().is_invertible()) or ( + ....: x.operator().inverse()(J.one()) == x.inverse() ) + True + """ if not self.is_invertible(): raise ValueError("element is not invertible") -- 2.44.2