Proof of `Sub-invariant functions of an ergodic system are constant`
groundedproofs/Lax606786Proofs/Kingman/ZeroOne.lean · lax-606786
What this proof establishes
no assumptions
Assuming the claims on the left, the claim on the right holds — checked by the archive's pipeline. Proof code is not displayed here.
Description
Each superlevel set is forward-invariant up to inclusion, hence null or conull.