| # rmdup(x0) = m0 + 1, # rmdup(a0 ' + x0) = m + 1, a ∈ x0, ∀ a. a ∈ x0 → # rmdup(x0 -l a) = m0 ⊦ 1 + # rmdup(x0 -l a) = m, a = a0, x0 = [], a0 ∈ x0 -l a |
⊦ a ∈ x → rmdup(a ' + x) = rmdup(x)
# rmdup(a0 ' + x0) = m + 1, # rmdup(x0) = m0 + 1, a ∈ x0, ∀ a. a ∈ x0 → # rmdup(x0 -l a) = m0 ⊦ 1 + # rmdup(x0 -l a) = m, a = a0, x0 = [], a0 ∈ x0 -l a, a0 ∈ x0
Used simplifier rules: in: ⊦ a ∈ x ∧ a ≠ b → a ∈ x -l b; Used terms: x0, a0