| ∀ i. # depths(t0, i) = 1 → t0 = Leaf, ∀ i. # depths(t1, i) = 1 → t1 = Leaf, # depths(Node(t0, t1), i) = 1 ⊦ Node(t0, t1) = Leaf |
⊦ depths(Node(t0, t1), i) = depths(t0, i + 1) + depths(t1, i + 1)
⊦ depths(Leaf, i) = i '
⊦ depths(t, i) ≠ []
# depths(t0, i + 1) + # depths(t1, i + 1) = 1 ⊦ t0 = Leaf, t1 = Leaf, ∃ i. # depths(t0, i) = 1, ∃ i. # depths(t1, i) = 1
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ m + n = n + m], [CSIMPSEQ : ⊦ (m + n0) + n1 = m + n0 + n1], [CSIMPSEQ : ⊦ # x = 0 ↔ x = []], [CSIMPSEQ : ⊦ 1 = m + 1 ↔ m = 0], [CSIMPSEQ : ⊦ # d ' = 0 +1], [CSIMPSEQ : ⊦ Leaf ≠ Node(t, t0)], [CSIMPSEQ : ⊦ (x + y) + z = x + y + z], [CSIMPSEQ : ⊦ # (x + y) = # x + # y])]]