| ∀ a, ay. a ∈ ax0 → (ax0 + ay)[a] = ax0[a] ⊦ a ∈ p + ax0 → ((p + ax0) + ay)[a] = (p + ax0)[a] |
∀ a, ay. a ∈ ax0 → (ax0 + ay)[a] = ax0[a] ⊦ ((p ' + ax0) + ay)[a] = (p ' + ax0)[a], ¬ a ∈ p ' ∧ ¬ a ∈ ax0
Used simplifier rules: inapp: ⊦ a ∈ ax + ay ↔ ¬ ¬(a ∈ ax ∨ a ∈ ay);% ⊦ (ax + ax0) + ax1 = ax + ax0 + ax1;% ⊦ p + ax = p ' + ax;