Metamath Proof Explorer


Definition df-submnd

Description: A submonoid is a subset of a monoid which contains the identity and is closed under the operation. Such subsets are themselves monoids with the same identity. (Contributed by Mario Carneiro, 7-Mar-2015)

Ref Expression
Assertion df-submnd SubMnd = ( 𝑠 ∈ Mnd ↦ { 𝑡 ∈ 𝒫 ( Base ‘ 𝑠 ) ∣ ( ( 0g𝑠 ) ∈ 𝑡 ∧ ∀ 𝑥𝑡𝑦𝑡 ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡 ) } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 csubmnd SubMnd
1 vs 𝑠
2 cmnd Mnd
3 vt 𝑡
4 cbs Base
5 1 cv 𝑠
6 5 4 cfv ( Base ‘ 𝑠 )
7 6 cpw 𝒫 ( Base ‘ 𝑠 )
8 c0g 0g
9 5 8 cfv ( 0g𝑠 )
10 3 cv 𝑡
11 9 10 wcel ( 0g𝑠 ) ∈ 𝑡
12 vx 𝑥
13 vy 𝑦
14 12 cv 𝑥
15 cplusg +g
16 5 15 cfv ( +g𝑠 )
17 13 cv 𝑦
18 14 17 16 co ( 𝑥 ( +g𝑠 ) 𝑦 )
19 18 10 wcel ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡
20 19 13 10 wral 𝑦𝑡 ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡
21 20 12 10 wral 𝑥𝑡𝑦𝑡 ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡
22 11 21 wa ( ( 0g𝑠 ) ∈ 𝑡 ∧ ∀ 𝑥𝑡𝑦𝑡 ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡 )
23 22 3 7 crab { 𝑡 ∈ 𝒫 ( Base ‘ 𝑠 ) ∣ ( ( 0g𝑠 ) ∈ 𝑡 ∧ ∀ 𝑥𝑡𝑦𝑡 ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡 ) }
24 1 2 23 cmpt ( 𝑠 ∈ Mnd ↦ { 𝑡 ∈ 𝒫 ( Base ‘ 𝑠 ) ∣ ( ( 0g𝑠 ) ∈ 𝑡 ∧ ∀ 𝑥𝑡𝑦𝑡 ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡 ) } )
25 0 24 wceq SubMnd = ( 𝑠 ∈ Mnd ↦ { 𝑡 ∈ 𝒫 ( Base ‘ 𝑠 ) ∣ ( ( 0g𝑠 ) ∈ 𝑡 ∧ ∀ 𝑥𝑡𝑦𝑡 ( 𝑥 ( +g𝑠 ) 𝑦 ) ∈ 𝑡 ) } )