| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opmpoismgm.b | ⊢ 𝐵  =  ( Base ‘ 𝑀 ) | 
						
							| 2 |  | opmpoismgm.p | ⊢ ( +g ‘ 𝑀 )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) | 
						
							| 3 |  | opmpoismgm.n | ⊢ ( 𝜑  →  𝐵  ≠  ∅ ) | 
						
							| 4 |  | opmpoismgm.c | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐵 ) )  →  𝐶  ∈  𝐵 ) | 
						
							| 5 | 4 | ralrimivva | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 𝐶  ∈  𝐵 ) | 
						
							| 6 | 5 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 𝐶  ∈  𝐵 ) | 
						
							| 7 |  | simprl | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  𝑎  ∈  𝐵 ) | 
						
							| 8 |  | simprr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  𝑏  ∈  𝐵 ) | 
						
							| 9 |  | eqid | ⊢ ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) | 
						
							| 10 | 9 | ovmpoelrn | ⊢ ( ( ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 𝐶  ∈  𝐵  ∧  𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 )  →  ( 𝑎 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) 𝑏 )  ∈  𝐵 ) | 
						
							| 11 | 6 7 8 10 | syl3anc | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐵  ∧  𝑏  ∈  𝐵 ) )  →  ( 𝑎 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) 𝑏 )  ∈  𝐵 ) | 
						
							| 12 | 11 | ralrimivva | ⊢ ( 𝜑  →  ∀ 𝑎  ∈  𝐵 ∀ 𝑏  ∈  𝐵 ( 𝑎 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) 𝑏 )  ∈  𝐵 ) | 
						
							| 13 |  | n0 | ⊢ ( 𝐵  ≠  ∅  ↔  ∃ 𝑒 𝑒  ∈  𝐵 ) | 
						
							| 14 | 2 | eqcomi | ⊢ ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 )  =  ( +g ‘ 𝑀 ) | 
						
							| 15 | 1 14 | ismgmn0 | ⊢ ( 𝑒  ∈  𝐵  →  ( 𝑀  ∈  Mgm  ↔  ∀ 𝑎  ∈  𝐵 ∀ 𝑏  ∈  𝐵 ( 𝑎 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) 𝑏 )  ∈  𝐵 ) ) | 
						
							| 16 | 15 | exlimiv | ⊢ ( ∃ 𝑒 𝑒  ∈  𝐵  →  ( 𝑀  ∈  Mgm  ↔  ∀ 𝑎  ∈  𝐵 ∀ 𝑏  ∈  𝐵 ( 𝑎 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) 𝑏 )  ∈  𝐵 ) ) | 
						
							| 17 | 13 16 | sylbi | ⊢ ( 𝐵  ≠  ∅  →  ( 𝑀  ∈  Mgm  ↔  ∀ 𝑎  ∈  𝐵 ∀ 𝑏  ∈  𝐵 ( 𝑎 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) 𝑏 )  ∈  𝐵 ) ) | 
						
							| 18 | 3 17 | syl | ⊢ ( 𝜑  →  ( 𝑀  ∈  Mgm  ↔  ∀ 𝑎  ∈  𝐵 ∀ 𝑏  ∈  𝐵 ( 𝑎 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  𝐶 ) 𝑏 )  ∈  𝐵 ) ) | 
						
							| 19 | 12 18 | mpbird | ⊢ ( 𝜑  →  𝑀  ∈  Mgm ) |