| tree = dnode(md0, sdt0), str ' ∈ tree ⊦ ∃ md, sdt. tree = dnode(md, sdt) ∧ str ∈ sdt |
⊦ str ' ∈ dnode(md, sdt) ↔ str ∈ sdt
str ∈ sdt0 ⊦ ∃ md, sdt. dnode(md0, sdt0) = dnode(md, sdt) ∧ str ∈ sdt
Used simplifier rules: one-ind: ⊦ str ' ∈ dnode(md, sdt) ↔ str ∈ sdt;