⊦ (∀ H1. H1 ⊥ H ∧ P0(H1) → P1(H1 ∪ H)) ↔ ¬(∃ H0. H0 ⊥ H ∧ P0(H0) ∧ ¬ P1(H0 ∪ H))
Used simplifier rules: not: ⊦ (¬ P0)(H) ↔ ¬ P0(H);