| a ∈ x ⊦ frome(x, a) = restn(pos(a, x), x) |
∀ a. a ∈ x0 → frome(x0, a) = restn(pos(a, x0), x0), a ∈ a0 + x0 ⊦ frome(a0 + x0, a) = restn(pos(a, a0 + x0), a0 + x0)
Used simplifier rules: fromE-empty: ⊦ frome([], a) = [];%pos-e: ⊦ pos(a, []) = 0;%restN-zero: ⊦ restn(0, x) = x;%list freely generated by [], +;;