| fid0 ∈ fs ↔ fid0 ∈ root0.fids ∨ fid0 ∈ ofh.fids, root0[path'] = fnode(fid), fnode(fid1) = 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 ⊦ fid0 ≠ fid ∧ fid0 ∈ fs ↔ fid0 ∈ ((root0.fids \ root0[path].fids) \ (path' ⊑ path ⊃ fnode(fid) -- restn(# path', path);fnode(fid)).fids) ∪ root0[path].fids ∨ fid0 ∈ ofh.fids, path' = ε, root0[path].dir?, fid ∈ root0[path].fids, fid ∈ (root0.fids \ root0[path].fids) \ (path' ⊑ path ⊃ fnode(fid) -- restn(# path', path);fnode(fid)).fids, fid ∈ ofh.fids, path ⊑ path' |
fid0 ∈ fs ↔ fid0 ∈ root0.fids ∨ fid0 ∈ ofh.fids, root0[path'] = fnode(fid), fnode(fid1) = 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 ⊦ fid0 ≠ fid ∧ fid0 ∈ fs ↔ fid0 ∈ ((root0.fids \ {fid1} ) \ (path' ⊑ path ⊃ fnode(fid) -- restn(# path', path);fnode(fid)).fids) ∪ {fid1} ∨ fid0 ∈ ofh.fids, fid = fid1, path' = ε, fid ∈ ofh.fids, fid ∈ (root0.fids \ {fid1} ) \ (path' ⊑ path ⊃ fnode(fid) -- restn(# path', path);fnode(fid)).fids, path ⊑ path'
Used simplifier rules: ⊦ fid ∈ {fid0} ↔ fid = fid0; (s)% ⊦ ¬ fnode(fid).dir?; (s)% ⊦ fnode(fid).fids = {fid} ; (s)