P(H0), oP(o)(H1), H1 ⊥ H0 ⊦ ((_∃ oP * P))(H1 ∪ H0), ∃ o. oP(o)(H1)
Used simplifier rules: ex3: ⊦ (_∃ oP)(H) ↔ (∃ o. oP(o)(H));