| # y < # filter(a ' + rmdup(x0), y), ∀ y. # y < # filter(rmdup(x0), y) → filter(rmdup(x0), y) = [] ⊦ filter(a ' + rmdup(x0), y) = [], a ∈ x0 |
a ∈ y, # y < # filter(a ' + rmdup(x0), y), ∀ y. # y < # filter(rmdup(x0), y) → filter(rmdup(x0), y) = [] ⊦ filter(a ' + rmdup(x0), y) = [], a ∈ x0
# y < # filter(a ' + rmdup(x0), y), ∀ y. # y < # filter(rmdup(x0), y) → filter(rmdup(x0), y) = [] ⊦ a ∈ y, filter(a ' + rmdup(x0), y) = [], a ∈ x0
Used formulas: a ∈ y