| H0 ⊥ H1, ∀ H, H0, r. # H < # H1 → H0 ⊥ H → (r ∈ H0 ∪ H ↔ r ∈ H0 ∨ r ∈ H) ⊦ r ∈ H0 ∪ H1 ↔ r ∈ H0 ∨ r ∈ H1 |
H0 ⊥ H1, ∀ H, H0, r. # H < # H1 → H0 ⊥ H → (r ∈ H0 ∪ H ↔ r ∈ H0 ∨ r ∈ H) ⊦ r ∈ H0 ∪ H1 ↔ r ∈ H0 ∨ r ∈ H1, H1 = ∅
Used simplifier rules: uni-emp-r: ⊦ H ∪ ∅ = H;%in-emp: ⊦ ¬ r ∈ ∅; Used formulas: H1 = ∅