case neg φ' =>
  simp_all
  subst c_in
  subst precond_eq
  if φ = φ'
  then simp_all
  else simp_all
α : Formula
R L : Finset Formula
α_in_R : α ∈ R
c : TNode
L_cond_in : ∅ ⊆ L
φ : Formula
precond_eq : {~~φ} = {α}
φ' : Formula
R_cond_in : {~~φ'} ⊆ R
c_in : c ∈ applyLocalRule (LocalRule.oneSidedR (OneSidedLocalRule.neg φ')) (L, R)
⊢ α ∈ c.2 ∨ ∃ res ∈ [{φ}], res ⊆ c.2
no goals