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