Metamath Proof Explorer


Theorem submmulgcl

Description: Closure of the group multiple (exponentiation) operation in a submonoid. (Contributed by Mario Carneiro, 13-Jan-2015)

Ref Expression
Hypothesis submmulgcl.t ⊢ ∙ = ( .g ‘ 𝐺 )
Assertion submmulgcl ( ( 𝑆 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑁 ∈ ℕ0 ∧ 𝑋 ∈ 𝑆 ) → ( 𝑁 ∙ 𝑋 ) ∈ 𝑆 )

Proof

Step Hyp Ref Expression
1 submmulgcl.t ⊢ ∙ = ( .g ‘ 𝐺 )
2 eqid ⊢ ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 )
3 eqid ⊢ ( +g ‘ 𝐺 ) = ( +g ‘ 𝐺 )
4 submrcl ⊢ ( 𝑆 ∈ ( SubMnd ‘ 𝐺 ) → 𝐺 ∈ Mnd )
5 2 submss ⊢ ( 𝑆 ∈ ( SubMnd ‘ 𝐺 ) → 𝑆 ⊆ ( Base ‘ 𝐺 ) )
6 3 submcl ⊢ ( ( 𝑆 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆 ) → ( 𝑥 ( +g ‘ 𝐺 ) 𝑦 ) ∈ 𝑆 )
7 eqid ⊢ ( 0g ‘ 𝐺 ) = ( 0g ‘ 𝐺 )
8 7 subm0cl ⊢ ( 𝑆 ∈ ( SubMnd ‘ 𝐺 ) → ( 0g ‘ 𝐺 ) ∈ 𝑆 )
9 2 1 3 4 5 6 7 8 mulgnn0subcl ⊢ ( ( 𝑆 ∈ ( SubMnd ‘ 𝐺 ) ∧ 𝑁 ∈ ℕ0 ∧ 𝑋 ∈ 𝑆 ) → ( 𝑁 ∙ 𝑋 ) ∈ 𝑆 )