| n < # y, y[n] ∈ y[n, a] -1l a ∨ y[n] ∈ y -1l y[n] ⊦ y = [], #oc(y[n], y[n, a] -1l a) = #oc(y[n], y -1l y[n]) |
⊦ a ∈ x → #oc(a, x -1l a) = #oc(a, x) -1
y[n] ∈ y, n < # y, y[n] ∈ y[n, a] -1l a ∨ y[n] ∈ y -1l y[n] ⊦ y = [], #oc(y[n], y[n, a] -1l a) = #oc(y[n], y) -1
Used simplifier rules: notin: ⊦ ¬ a ∈ x → #oc(a, x) = 0;%oc-zero: ⊦ #oc(a, x) = 0 ↔ ¬ a ∈ x;%in-02-01: ⊦ ¬ a ∈ x → x -1l a = x; from specification list-del%get-in: ⊦ m < # x → (¬ x[m] ∈ x ↔ false); from specification list-del Used terms: y, y[n]