| fid ∈ fs ↔ fid ∈ root0.fids ∨ fid ∈ ofh.fids, root0[path'] = fnode(fid1), fnode(fid0) = root0[path], (root0 -- path)[parent(path')].dir?, root0[parent(path')].dir?, fids-cons(root0, fs, ofh), py(user, parent(path), root0, fs), py(user, parent(path'), root0, fs), path' ∈ root0, path ∈ root0, parent(path') ∈ root0 ⊦ fid ∈ fs ↔ fid ∈ ((root0.fids \ {fid0} ) \ (path' ⊑ path ⊃ fnode(fid1) -- restn(# path', path);fnode(fid1)).fids) ∪ {fid0} ∨ fid ∈ ofh.fids, path' = ε, path ⊑ path', ¬ fid1 ∈ ofh.fids ∧ ¬ fid1 ∈ ((root0.fids \ {fid0} ) \ (path' ⊑ path ⊃ fnode(fid1) -- restn(# path', path);fnode(fid1)).fids) ∪ {fid0} |
⊦ fid ∈ fidb ∪ fidb0 ↔ fid ∈ fidb ∨ fid ∈ fidb0
fid ∈ fs ↔ fid ∈ root0.fids ∨ fid ∈ ofh.fids, root0[path'] = fnode(fid1), fnode(fid0) = root0[path], root0[parent(path')].dir?, (root0 -- path)[parent(path')].dir?, fids-cons(root0, fs, ofh), py(user, parent(path'), root0, fs), py(user, parent(path), root0, fs), parent(path') ∈ root0, path ∈ root0, path' ∈ root0 ⊦ fid ∈ fs ↔ (fid ∈ (root0.fids \ {fid0} ) \ (path' ⊑ path ⊃ fnode(fid1) -- restn(# path', path);fnode(fid1)).fids ∨ fid ∈ {fid0} ) ∨ fid ∈ ofh.fids, path' = ε, path ⊑ path', ¬ fid1 ∈ ofh.fids ∧ ¬ fid1 ∈ ((root0.fids \ {fid0} ) \ (path' ⊑ path ⊃ fnode(fid1) -- restn(# path', path);fnode(fid1)).fids) ∪ {fid0}
Used terms: {fid0} , (root0.fids \ {fid0} ) \ (path' ⊑ path ⊃ fnode(fid1) -- restn(# path', path);fnode(fid1)) .fids, fid