| ⊦ (x -1l a) -l a ⊆m y -l a ∧ #oc(a, x -1l a) ≤ #oc(a, y) ↔ x -l a ⊆m y -l a ∧ #oc(a, x) ≤ #oc(a, y) + 1 |
x -l a ⊆m y -l a ⊦ #oc(a, x -1l a) ≤ #oc(a, y) ↔ #oc(a, x) ≤ #oc(a, y) + 1
Used simplifier rules: del1-del: ⊦ (x -1l a) -l a = x -l a; from specification list-del