SETUP::
- sage: from mjo.eja.eja_algebra import RealSymmetricEJA, random_eja
+ sage: from mjo.eja.eja_algebra import (RealSymmetricEJA,
+ ....: TrivialEJA,
+ ....: random_eja)
EXAMPLES::
sage: x.operator().is_invertible()
True
+ The zero operator is invertible in a trivial algebra::
+
+ sage: J = TrivialEJA()
+ sage: J.zero().operator().is_invertible()
+ True
+
TESTS:
The identity operator is always invertible::