| ∀ a. a ∈ list2set(x0) ↔ a ∈ x0 ⊦ a0 = a ∨ a0 ∈ list2set(x0) ↔ a0 = a ∨ a0 ∈ x0 |
a0 ∈ x0, ∀ a. a ∈ list2set(x0) ↔ a ∈ x0 ⊦ a0 = a ∨ a0 ∈ list2set(x0) ↔ a0 = a ∨ a0 ∈ x0
∀ a. a ∈ list2set(x0) ↔ a ∈ x0 ⊦ a0 ∈ x0, a0 = a ∨ a0 ∈ list2set(x0) ↔ a0 = a ∨ a0 ∈ x0
Used formulas: a0 ∈ x0