| x ⊆m x0, a ∈ y0, y1 ⊆m y0 -1l a, ∀ x, x0, y0. x ⊆m x0 ∧ y1 ⊆m y0 → y1 + x ⊆m x0 + y0 ⊦ y1 + x ⊆m (x0 + y0) -1l a |
Used simplifier rules: subdel-01: ⊦ x ⊆m y + (y0 -1l a) ∧ a ∈ y0 → x ⊆m (y + y0) -1l a;%a: ⊦ (x + y) + z = x + y + z; from specification list Used terms: x, x0, y0 -1l a