Module: Mathlib.Algebra.Order.Module.HahnEmbedding

Goal state before:
pp: case pos
K : Type u_1
inst✝¹¹ : DivisionRing K
inst✝¹⁰ : LinearOrder K
inst✝⁹ : IsOrderedRing K
inst✝⁸ : Archimedean K
M : Type u_2
inst✝⁷ : AddCommGroup M
inst✝⁶ : LinearOrder M
inst✝⁵ : IsOrderedAddMonoid M
inst✝⁴ : Module K M
inst✝³ : IsOrderedModule K M
R : Type u_3
inst✝² : AddCommGroup R
inst✝¹ : LinearOrder R
inst✝ : Module K R
seed : Seed K M R
x : ↥seed.baseEmbedding.domain
hx : 0 < x
hmem : ↑x ∈ seed.baseDomain
f : Π₀ (i : FiniteArchimedeanClass M), ↥(seed.stratum i)
hf : (f.sum fun x xi ↦ ↑xi) = ↑x
hfpos : 0 < f.sum fun x x_1 ↦ ↑x_1
hsupport : f.support.Nonempty
hferase :
  (f.sum fun x x_1 ↦ ↑x_1) - ↑(f (f.support.min' hsupport)) = ∑ x ∈ f.support.erase (f.support.min' hsupport), ↑(f x)
hmono : StrictMonoOn (fun x ↦ ArchimedeanClass.mk ↑(f x)) ↑f.support
hsupport' : (f.support.erase (f.support.min' hsupport)).Nonempty
⊢ ↑(f.support.min' hsupport) < ArchimedeanClass.mk (∑ x ∈ f.support.erase (f.support.min' hsupport), ↑(f x))

pp: case neg
K : Type u_1
inst✝¹¹ : DivisionRing K
inst✝¹⁰ : LinearOrder K
inst✝⁹ : IsOrderedRing K
inst✝⁸ : Archimedean K
M : Type u_2
inst✝⁷ : AddCommGroup M
inst✝⁶ : LinearOrder M
inst✝⁵ : IsOrderedAddMonoid M
inst✝⁴ : Module K M
inst✝³ : IsOrderedModule K M
R : Type u_3
inst✝² : AddCommGroup R
inst✝¹ : LinearOrder R
inst✝ : Module K R
seed : Seed K M R
x : ↥seed.baseEmbedding.domain
hx : 0 < x
hmem : ↑x ∈ seed.baseDomain
f : Π₀ (i : FiniteArchimedeanClass M), ↥(seed.stratum i)
hf : (f.sum fun x xi ↦ ↑xi) = ↑x
hfpos : 0 < f.sum fun x x_1 ↦ ↑x_1
hsupport : f.support.Nonempty
hferase :
  (f.sum fun x x_1 ↦ ↑x_1) - ↑(f (f.support.min' hsupport)) = ∑ x ∈ f.support.erase (f.support.min' hsupport), ↑(f x)
hmono : StrictMonoOn (fun x ↦ ArchimedeanClass.mk ↑(f x)) ↑f.support
hsupport' : f.support.erase (f.support.min' hsupport) = ∅
⊢ ↑(f.support.min' hsupport) < ArchimedeanClass.mk (∑ x ∈ f.support.erase (f.support.min' hsupport), ↑(f x))

Tactic:
· rw [ArchimedeanClass.mk_sum hsupport' (hmono.mono (by simp))]
    rw [seed.archimedeanClassMk_of_mem_stratum (f _).prop (by
      simpa using! (Finset.mem_erase.mp <| (f.support.erase _).min'_mem hsupport').2)]
    apply Finset.min'_lt_of_mem_erase_min' (α := FiniteArchimedeanClass M)
    apply Finset.min'_mem _ _

Goal state after:
case neg
K : Type u_1
inst✝¹¹ : DivisionRing K
inst✝¹⁰ : LinearOrder K
inst✝⁹ : IsOrderedRing K
inst✝⁸ : Archimedean K
M : Type u_2
inst✝⁷ : AddCommGroup M
inst✝⁶ : LinearOrder M
inst✝⁵ : IsOrderedAddMonoid M
inst✝⁴ : Module K M
inst✝³ : IsOrderedModule K M
R : Type u_3
inst✝² : AddCommGroup R
inst✝¹ : LinearOrder R
inst✝ : Module K R
seed : Seed K M R
x : ↥seed.baseEmbedding.domain
hx : 0 < x
hmem : ↑x ∈ seed.baseDomain
f : Π₀ (i : FiniteArchimedeanClass M), ↥(seed.stratum i)
hf : (f.sum fun x xi ↦ ↑xi) = ↑x
hfpos : 0 < f.sum fun x x_1 ↦ ↑x_1
hsupport : f.support.Nonempty
hferase :
  (f.sum fun x x_1 ↦ ↑x_1) - ↑(f (f.support.min' hsupport)) = ∑ x ∈ f.support.erase (f.support.min' hsupport), ↑(f x)
hmono : StrictMonoOn (fun x ↦ ArchimedeanClass.mk ↑(f x)) ↑f.support
hsupport' : f.support.erase (f.support.min' hsupport) = ∅
⊢ ↑(f.support.min' hsupport) < ArchimedeanClass.mk (∑ x ∈ f.support.erase (f.support.min' hsupport), ↑(f x))