| ∀ fid. (fid ∈ fs0 ↔ fid ∈ tree0.fids ∨ fid ∈ ofh0.fids) → (fid ∈ fs1 ↔ fid ∈ tree1.fids ∨ fid ∈ ofh1.fids), ∀ fid. fid ∈ fs0 ↔ fid ∈ tree0.fids ∨ fid ∈ ofh0.fids ⊦ fid ∈ fs1 ↔ fid ∈ tree1.fids ∨ fid ∈ ofh1.fids |
(fid ∈ fs0 ↔ fid ∈ tree0.fids ∨ fid ∈ ofh0.fids) → (fid ∈ fs1 ↔ fid ∈ tree1.fids ∨ fid ∈ ofh1.fids), ∀ fid. fid ∈ fs0 ↔ fid ∈ tree0.fids ∨ fid ∈ ofh0.fids, ∀ fid. (fid ∈ fs0 ↔ fid ∈ tree0.fids ∨ fid ∈ ofh0.fids) → (fid ∈ fs1 ↔ fid ∈ tree1.fids ∨ fid ∈ ofh1.fids) ⊦ fid ∈ fs1 ↔ fid ∈ tree1.fids ∨ fid ∈ ofh1.fids
Used terms: fid