Theorem: closure_smul₀
File: Mathlib/Topology/Algebra/ConstMulAction.lean

tactic: rcases eq_or_ne c 0 with (rfl | hc)
state_before: M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c✝ : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
c : G₀
s : Set E
⊢ closure (c • s) = c • closure s
state_after: case inl
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
s : Set E
⊢ closure (0 • s) = 0 • closure s

case inr
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c✝ : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
c : G₀
s : Set E
hc : c ≠ 0
⊢ closure (c • s) = c • closure s

tactic: rcases eq_empty_or_nonempty s with (rfl | hs)
state_before: case inl
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
s : Set E
⊢ closure (0 • s) = 0 • closure s
state_after: case inl.inl
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
⊢ closure (0 • ∅) = 0 • closure ∅

case inl.inr
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
s : Set E
hs : s.Nonempty
⊢ closure (0 • s) = 0 • closure s

tactic: simp
state_before: case inl.inl
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
⊢ closure (0 • ∅) = 0 • closure ∅
state_after: no goals

tactic: rw [zero_smul_set hs, zero_smul_set hs.closure]
state_before: case inl.inr
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
s : Set E
hs : s.Nonempty
⊢ closure (0 • s) = 0 • closure s
state_after: case inl.inr
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
s : Set E
hs : s.Nonempty
⊢ closure 0 = 0

tactic: exact closure_singleton
state_before: case inl.inr
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
s : Set E
hs : s.Nonempty
⊢ closure 0 = 0
state_after: no goals

tactic: exact closure_smul₀' hc s
state_before: case inr
M : Type u_1
α : Type u_2
β : Type u_3
G₀ : Type u_4
inst✝⁹ : TopologicalSpace α
inst✝⁸ : GroupWithZero G₀
inst✝⁷ : MulAction G₀ α
inst✝⁶ : ContinuousConstSMul G₀ α
inst✝⁵ : TopologicalSpace β
f : β → α
b : β
c✝ : G₀
s✝ : Set β
E : Type u_5
inst✝⁴ : Zero E
inst✝³ : MulActionWithZero G₀ E
inst✝² : TopologicalSpace E
inst✝¹ : T1Space E
inst✝ : ContinuousConstSMul G₀ E
c : G₀
s : Set E
hc : c ≠ 0
⊢ closure (c • s) = c • closure s
state_after: no goals