simp[disjointPCs, Set.split]
F : Type
p : ConfigPartition
pc : PC F
⊢ disjointPCs (Set.split (PC F) p.pcs fun p => (pc &&& p, ~~~pc &&& p))
F : Type
p : ConfigPartition
pc : PC F
⊢ ∀ (c : Config F) (a : PC F),
    ((∃ x ∈ p.pcs, pc &&& x = a) ∨ ∃ x ∈ p.pcs, ~~~pc &&& x = a) →
      ∀ (a_1 : PC F), ((∃ x ∈ p.pcs, pc &&& x = a_1) ∨ ∃ x ∈ p.pcs, ~~~pc &&& x = a_1) → c ∈ ⦃a⦄ → c ∈ ⦃a_1⦄ → a = a_1