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 ) | 
| 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 ) |