| nx.last ∈ nx.butlast ⊦ nx = [], dups(nx) |
⊦ nx = [] ↔ ¬(∃ nx0, n. nx = nx0 + n ')
Used simplifier rules: ⊦ (nx + n ').last = n; (s)%a: ⊦ (nx + nx0) + nx1 = nx + nx0 + nx1; from specification list[nat-list-set]% ⊦ (nx + n ').butlast = nx; (s)% ⊦ n ∈ nx → dups(nx + n '); (s) Used terms: nx