| H0 ⊥ H1, H1 ⊥ H, H ⊥ H0 ⊦ ∀ r. (r ∈ (H0 ∪ H1) ∪ H ↔ r ∈ H0 ∪ H1 ∪ H) ∧ (r ∈ (H0 ∪ H1) ∪ H → ((H0 ∪ H1) ∪ H)[r] = (H0 ∪ H1 ∪ H)[r]) |
H ⊥ H0, H1 ⊥ H, H0 ⊥ H1 ⊦ (r ∈ (H0 ∪ H1) ∪ H ↔ r ∈ H0 ∪ H1 ∪ H) ∧ (r ∈ (H0 ∪ H1) ∪ H → ((H0 ∪ H1) ∪ H)[r] = (H0 ∪ H1 ∪ H)[r])