| Step | Hyp | Ref | Expression | 
						
							| 0 |  | csubmgm | ⊢ SubMgm | 
						
							| 1 |  | vs | ⊢ 𝑠 | 
						
							| 2 |  | cmgm | ⊢ Mgm | 
						
							| 3 |  | vt | ⊢ 𝑡 | 
						
							| 4 |  | cbs | ⊢ Base | 
						
							| 5 | 1 | cv | ⊢ 𝑠 | 
						
							| 6 | 5 4 | cfv | ⊢ ( Base ‘ 𝑠 ) | 
						
							| 7 | 6 | cpw | ⊢ 𝒫  ( Base ‘ 𝑠 ) | 
						
							| 8 |  | vx | ⊢ 𝑥 | 
						
							| 9 | 3 | cv | ⊢ 𝑡 | 
						
							| 10 |  | vy | ⊢ 𝑦 | 
						
							| 11 | 8 | cv | ⊢ 𝑥 | 
						
							| 12 |  | cplusg | ⊢ +g | 
						
							| 13 | 5 12 | cfv | ⊢ ( +g ‘ 𝑠 ) | 
						
							| 14 | 10 | cv | ⊢ 𝑦 | 
						
							| 15 | 11 14 13 | co | ⊢ ( 𝑥 ( +g ‘ 𝑠 ) 𝑦 ) | 
						
							| 16 | 15 9 | wcel | ⊢ ( 𝑥 ( +g ‘ 𝑠 ) 𝑦 )  ∈  𝑡 | 
						
							| 17 | 16 10 9 | wral | ⊢ ∀ 𝑦  ∈  𝑡 ( 𝑥 ( +g ‘ 𝑠 ) 𝑦 )  ∈  𝑡 | 
						
							| 18 | 17 8 9 | wral | ⊢ ∀ 𝑥  ∈  𝑡 ∀ 𝑦  ∈  𝑡 ( 𝑥 ( +g ‘ 𝑠 ) 𝑦 )  ∈  𝑡 | 
						
							| 19 | 18 3 7 | crab | ⊢ { 𝑡  ∈  𝒫  ( Base ‘ 𝑠 )  ∣  ∀ 𝑥  ∈  𝑡 ∀ 𝑦  ∈  𝑡 ( 𝑥 ( +g ‘ 𝑠 ) 𝑦 )  ∈  𝑡 } | 
						
							| 20 | 1 2 19 | cmpt | ⊢ ( 𝑠  ∈  Mgm  ↦  { 𝑡  ∈  𝒫  ( Base ‘ 𝑠 )  ∣  ∀ 𝑥  ∈  𝑡 ∀ 𝑦  ∈  𝑡 ( 𝑥 ( +g ‘ 𝑠 ) 𝑦 )  ∈  𝑡 } ) | 
						
							| 21 | 0 20 | wceq | ⊢ SubMgm  =  ( 𝑠  ∈  Mgm  ↦  { 𝑡  ∈  𝒫  ( Base ‘ 𝑠 )  ∣  ∀ 𝑥  ∈  𝑡 ∀ 𝑦  ∈  𝑡 ( 𝑥 ( +g ‘ 𝑠 ) 𝑦 )  ∈  𝑡 } ) |