sage: from mjo.eja.eja_algebra import random_eja
- TESTS::
+ TESTS:
+
+ Ensure that we can find an idempotent in a non-trivial algebra
+ where there are non-nilpotent elements::
sage: set_random_seed()
- sage: J = random_eja()
+ sage: J = random_eja(nontrivial=True)
sage: x = J.random_element()
sage: while x.is_nilpotent():
....: x = J.random_element()
True
"""
+ if self.parent().is_trivial():
+ return self
+
if self.is_nilpotent():
raise ValueError("this only works with non-nilpotent elements!")