| unique_al(ax), perm(ax, ay), ∃ d. a × d ∈ ax, perm(ay, ax), unique_al(ay) ⊦ ax[a] = ay[a] |
unique_al(ay), perm(ay, ax), a × d ∈ ax, perm(ax, ay), unique_al(ax) ⊦ ax[a] = ay[a]
Used simplifier rules: unique-02: ⊦ unique_al(ax) ∧ a × d ∈ ax ∧ a × d0 ∈ ax → d = d0;