Identifiability in Inverse Reinforcement Learning: Supplementary Material A Appendix: Proofs of Results Proof of Theorem 1. Fix

Combining these inequalities, along with the fact γ < 1, we conclude that g (s) 0 for all s S . Hence, as γ < 1, we conclude that g (s) 0 for all s S . Given we know both agents' policies ( As R is closed under addition, we see that c = λa + µb R . Therefore, all states can be accessed from s. If the starting state is ephemeral, it is clear that we can add a constant to its rewards independently of all other states' rewards, as this will not affect decision Proof of Theorem 4. We first prove the sufficiency statement.