exact Δ_U_1
case h2
P U : Formula
Δ_U : Finset Formula
Δ_U_1 : U ∉ Δ_U
Δ_U_2 :
  Δ_U ⊆ P.primeSet → (∀ (V : VarBoolAssignment), IsDeduct (↑(Finset.image (evalPrimeFfToNot V) Δ_U)) P) → IsDeduct ∅ P
h2 : ∀ (V : VarBoolAssignment), IsDeduct (insert (evalPrimeFfToNot V U) (evalPrimeFfToNot V '' ↑Δ_U)) P
h1_left : U ∈ P.primeSet
h1_right : Δ_U ⊆ P.primeSet
⊢ U ∉ ↑Δ_U
no goals