| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ablsimpnosubgd.1 | ⊢ 𝐵  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | ablsimpnosubgd.2 | ⊢  0   =  ( 0g ‘ 𝐺 ) | 
						
							| 3 |  | ablsimpnosubgd.3 | ⊢ ( 𝜑  →  𝐺  ∈  Abel ) | 
						
							| 4 |  | ablsimpnosubgd.4 | ⊢ ( 𝜑  →  𝐺  ∈  SimpGrp ) | 
						
							| 5 |  | ablsimpnosubgd.5 | ⊢ ( 𝜑  →  𝑆  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 6 |  | ablsimpnosubgd.6 | ⊢ ( 𝜑  →  𝐴  ∈  𝑆 ) | 
						
							| 7 |  | ablsimpnosubgd.7 | ⊢ ( 𝜑  →  ¬  𝐴  =   0  ) | 
						
							| 8 |  | elsni | ⊢ ( 𝐴  ∈  {  0  }  →  𝐴  =   0  ) | 
						
							| 9 | 7 8 | nsyl | ⊢ ( 𝜑  →  ¬  𝐴  ∈  {  0  } ) | 
						
							| 10 |  | eleq2 | ⊢ ( 𝑆  =  {  0  }  →  ( 𝐴  ∈  𝑆  ↔  𝐴  ∈  {  0  } ) ) | 
						
							| 11 | 6 10 | syl5ibcom | ⊢ ( 𝜑  →  ( 𝑆  =  {  0  }  →  𝐴  ∈  {  0  } ) ) | 
						
							| 12 | 9 11 | mtod | ⊢ ( 𝜑  →  ¬  𝑆  =  {  0  } ) | 
						
							| 13 | 12 | pm2.21d | ⊢ ( 𝜑  →  ( 𝑆  =  {  0  }  →  𝑆  =  𝐵 ) ) | 
						
							| 14 |  | idd | ⊢ ( 𝜑  →  ( 𝑆  =  𝐵  →  𝑆  =  𝐵 ) ) | 
						
							| 15 |  | ablnsg | ⊢ ( 𝐺  ∈  Abel  →  ( NrmSGrp ‘ 𝐺 )  =  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 16 | 15 | eqcomd | ⊢ ( 𝐺  ∈  Abel  →  ( SubGrp ‘ 𝐺 )  =  ( NrmSGrp ‘ 𝐺 ) ) | 
						
							| 17 | 3 16 | syl | ⊢ ( 𝜑  →  ( SubGrp ‘ 𝐺 )  =  ( NrmSGrp ‘ 𝐺 ) ) | 
						
							| 18 | 5 17 | eleqtrd | ⊢ ( 𝜑  →  𝑆  ∈  ( NrmSGrp ‘ 𝐺 ) ) | 
						
							| 19 | 1 2 4 18 | simpgnsgeqd | ⊢ ( 𝜑  →  ( 𝑆  =  {  0  }  ∨  𝑆  =  𝐵 ) ) | 
						
							| 20 | 13 14 19 | mpjaod | ⊢ ( 𝜑  →  𝑆  =  𝐵 ) |