apply Nat.ne_of_gt
case h.left.h.inl.h
ν : Type u_1
s : LawfulState ν
n : ℕ
σ σ' : PropAssignment IVar
h1 :
  PropAssignment.map Sum.inl (PropAssignment.map (⇑{ toFun := State.withTemps.vMap s.toState, inj' := ⋯ }) σ') =
    PropAssignment.map s.vMap σ
v : ν
x : Fin n
this : ↑(s.vMap v) < ↑s.nextVar
⊢ ¬↑s.nextVar + ↑x = ↑(s.vMap v)
case h.left.h.inl.h.h
ν : Type u_1
s : LawfulState ν
n : ℕ
σ σ' : PropAssignment IVar
h1 :
  PropAssignment.map Sum.inl (PropAssignment.map (⇑{ toFun := State.withTemps.vMap s.toState, inj' := ⋯ }) σ') =
    PropAssignment.map s.vMap σ
v : ν
x : Fin n
this : ↑(s.vMap v) < ↑s.nextVar
⊢ ↑(s.vMap v) < ↑s.nextVar + ↑x