Module: Mathlib.MeasureTheory.Measure.Haar.Quotient

Goal state before:
pp: case cpos.a
G : Type u_1
inst✝¹⁴ : Group G
inst✝¹³ : MeasurableSpace G
inst✝¹² : TopologicalSpace G
inst✝¹¹ : IsTopologicalGroup G
inst✝¹⁰ : BorelSpace G
inst✝⁹ : PolishSpace G
Γ : Subgroup G
inst✝⁸ : Γ.Normal
inst✝⁷ : T2Space (G ⧸ Γ)
inst✝⁶ : SecondCountableTopology (G ⧸ Γ)
μ : Measure (G ⧸ Γ)
inst✝⁵ : Countable ↥Γ
ν : Measure G
inst✝⁴ : ν.IsHaarMeasure
inst✝³ : ν.IsMulRightInvariant
inst✝² : LocallyCompactSpace G
inst✝¹ : QuotientMeasureEqMeasurePreimage ν μ
inst✝ : IsFiniteMeasure μ
K : PositiveCompacts G
K' : PositiveCompacts (G ⧸ Γ) := ⋯
this : μ.IsMulLeftInvariant
s : Set G
finiteCovol : ν s ≠ ∞
fund_dom_s : IsFundamentalDomain (↥Γ.op) s ν
h : ν (Quotient.mk (MulAction.orbitRel (↥Γ.op) G) ⁻¹' ↑K' ∩ s) = 0
i' : ν.IsOpenPosMeasure
⊢ IsOpen (interior ↑K)

pp: case cpos.a
G : Type u_1
inst✝¹⁴ : Group G
inst✝¹³ : MeasurableSpace G
inst✝¹² : TopologicalSpace G
inst✝¹¹ : IsTopologicalGroup G
inst✝¹⁰ : BorelSpace G
inst✝⁹ : PolishSpace G
Γ : Subgroup G
inst✝⁸ : Γ.Normal
inst✝⁷ : T2Space (G ⧸ Γ)
inst✝⁶ : SecondCountableTopology (G ⧸ Γ)
μ : Measure (G ⧸ Γ)
inst✝⁵ : Countable ↥Γ
ν : Measure G
inst✝⁴ : ν.IsHaarMeasure
inst✝³ : ν.IsMulRightInvariant
inst✝² : LocallyCompactSpace G
inst✝¹ : QuotientMeasureEqMeasurePreimage ν μ
inst✝ : IsFiniteMeasure μ
K : PositiveCompacts G
K' : PositiveCompacts (G ⧸ Γ) := ⋯
this : μ.IsMulLeftInvariant
s : Set G
finiteCovol : ν s ≠ ∞
fund_dom_s : IsFundamentalDomain (↥Γ.op) s ν
h : ν (Quotient.mk (MulAction.orbitRel (↥Γ.op) G) ⁻¹' ↑K' ∩ s) = 0
i' : ν.IsOpenPosMeasure
⊢ (interior ↑K).Nonempty

pp: case cpos.a
G : Type u_1
inst✝¹⁴ : Group G
inst✝¹³ : MeasurableSpace G
inst✝¹² : TopologicalSpace G
inst✝¹¹ : IsTopologicalGroup G
inst✝¹⁰ : BorelSpace G
inst✝⁹ : PolishSpace G
Γ : Subgroup G
inst✝⁸ : Γ.Normal
inst✝⁷ : T2Space (G ⧸ Γ)
inst✝⁶ : SecondCountableTopology (G ⧸ Γ)
μ : Measure (G ⧸ Γ)
inst✝⁵ : Countable ↥Γ
ν : Measure G
inst✝⁴ : ν.IsHaarMeasure
inst✝³ : ν.IsMulRightInvariant
inst✝² : LocallyCompactSpace G
inst✝¹ : QuotientMeasureEqMeasurePreimage ν μ
inst✝ : IsFiniteMeasure μ
K : PositiveCompacts G
K' : PositiveCompacts (G ⧸ Γ) := ⋯
this : μ.IsMulLeftInvariant
s : Set G
finiteCovol : ν s ≠ ∞
fund_dom_s : IsFundamentalDomain (↥Γ.op) s ν
h : ν (Quotient.mk (MulAction.orbitRel (↥Γ.op) G) ⁻¹' ↑K' ∩ s) = 0
i' : ν.IsOpenPosMeasure
⊢ ν (interior ↑K) = 0

Tactic:
· exact isOpen_interior

Goal state after:
case cpos.a
G : Type u_1
inst✝¹⁴ : Group G
inst✝¹³ : MeasurableSpace G
inst✝¹² : TopologicalSpace G
inst✝¹¹ : IsTopologicalGroup G
inst✝¹⁰ : BorelSpace G
inst✝⁹ : PolishSpace G
Γ : Subgroup G
inst✝⁸ : Γ.Normal
inst✝⁷ : T2Space (G ⧸ Γ)
inst✝⁶ : SecondCountableTopology (G ⧸ Γ)
μ : Measure (G ⧸ Γ)
inst✝⁵ : Countable ↥Γ
ν : Measure G
inst✝⁴ : ν.IsHaarMeasure
inst✝³ : ν.IsMulRightInvariant
inst✝² : LocallyCompactSpace G
inst✝¹ : QuotientMeasureEqMeasurePreimage ν μ
inst✝ : IsFiniteMeasure μ
K : PositiveCompacts G
K' : PositiveCompacts (G ⧸ Γ) := ⋯
this : μ.IsMulLeftInvariant
s : Set G
finiteCovol : ν s ≠ ∞
fund_dom_s : IsFundamentalDomain (↥Γ.op) s ν
h : ν (Quotient.mk (MulAction.orbitRel (↥Γ.op) G) ⁻¹' ↑K' ∩ s) = 0
i' : ν.IsOpenPosMeasure
⊢ (interior ↑K).Nonempty

case cpos.a
G : Type u_1
inst✝¹⁴ : Group G
inst✝¹³ : MeasurableSpace G
inst✝¹² : TopologicalSpace G
inst✝¹¹ : IsTopologicalGroup G
inst✝¹⁰ : BorelSpace G
inst✝⁹ : PolishSpace G
Γ : Subgroup G
inst✝⁸ : Γ.Normal
inst✝⁷ : T2Space (G ⧸ Γ)
inst✝⁶ : SecondCountableTopology (G ⧸ Γ)
μ : Measure (G ⧸ Γ)
inst✝⁵ : Countable ↥Γ
ν : Measure G
inst✝⁴ : ν.IsHaarMeasure
inst✝³ : ν.IsMulRightInvariant
inst✝² : LocallyCompactSpace G
inst✝¹ : QuotientMeasureEqMeasurePreimage ν μ
inst✝ : IsFiniteMeasure μ
K : PositiveCompacts G
K' : PositiveCompacts (G ⧸ Γ) := ⋯
this : μ.IsMulLeftInvariant
s : Set G
finiteCovol : ν s ≠ ∞
fund_dom_s : IsFundamentalDomain (↥Γ.op) s ν
h : ν (Quotient.mk (MulAction.orbitRel (↥Γ.op) G) ⁻¹' ↑K' ∩ s) = 0
i' : ν.IsOpenPosMeasure
⊢ ν (interior ↑K) = 0