case neg φ' =>
  simp_all
  subst c_in
  subst precond_eq
  if φ = φ'
  then simp_all
  else simp_all
α : Formula
L R : Finset Formula
α_in_L : α ∈ L
c : TNode
R_cond_in : ∅ ⊆ R
φ : Formula
precond_eq : {~~φ} = {α}
φ' : Formula
L_cond_in : {~~φ'} ⊆ L
c_in : c ∈ applyLocalRule (LocalRule.oneSidedL (OneSidedLocalRule.neg φ')) (L, R)
⊢ α ∈ c.1 ∨ ∃ res ∈ [{φ}], res ⊆ c.1
no goals