| ⊦ a0 ∈ ax0 ∧ (∀ a, ay. a ∈ ax0 → (ax0 + ay)[a] = ax0[a]) → (((a × d)' + ax0) + ay)[a0] = ((a × d)' + ax0)[a0] ∨ a0 ∈ (a × d)' |
a0 ∈ ax0, ∀ a, ay. a ∈ ax0 → (ax0 + ay)[a] = ax0[a] ⊦ a0 = a, (ax0 + ay)[a0] = ax0[a0]
Used simplifier rules: inone: ⊦ a ∈ (b × d0)' ↔ a = b;%assoc-no: ⊦ a ≠ b → ((b × d)' + ax)[a] = ax[a];% ⊦ (ax + ax0) + ax1 = ax + ax0 + ax1;