| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 0 | 
							
								
							 | 
							cminusg | 
							⊢ invg  | 
						
						
							| 1 | 
							
								
							 | 
							vg | 
							⊢ 𝑔  | 
						
						
							| 2 | 
							
								
							 | 
							cvv | 
							⊢ V  | 
						
						
							| 3 | 
							
								
							 | 
							vx | 
							⊢ 𝑥  | 
						
						
							| 4 | 
							
								
							 | 
							cbs | 
							⊢ Base  | 
						
						
							| 5 | 
							
								1
							 | 
							cv | 
							⊢ 𝑔  | 
						
						
							| 6 | 
							
								5 4
							 | 
							cfv | 
							⊢ ( Base ‘ 𝑔 )  | 
						
						
							| 7 | 
							
								
							 | 
							vw | 
							⊢ 𝑤  | 
						
						
							| 8 | 
							
								7
							 | 
							cv | 
							⊢ 𝑤  | 
						
						
							| 9 | 
							
								
							 | 
							cplusg | 
							⊢ +g  | 
						
						
							| 10 | 
							
								5 9
							 | 
							cfv | 
							⊢ ( +g ‘ 𝑔 )  | 
						
						
							| 11 | 
							
								3
							 | 
							cv | 
							⊢ 𝑥  | 
						
						
							| 12 | 
							
								8 11 10
							 | 
							co | 
							⊢ ( 𝑤 ( +g ‘ 𝑔 ) 𝑥 )  | 
						
						
							| 13 | 
							
								
							 | 
							c0g | 
							⊢ 0g  | 
						
						
							| 14 | 
							
								5 13
							 | 
							cfv | 
							⊢ ( 0g ‘ 𝑔 )  | 
						
						
							| 15 | 
							
								12 14
							 | 
							wceq | 
							⊢ ( 𝑤 ( +g ‘ 𝑔 ) 𝑥 )  =  ( 0g ‘ 𝑔 )  | 
						
						
							| 16 | 
							
								15 7 6
							 | 
							crio | 
							⊢ ( ℩ 𝑤  ∈  ( Base ‘ 𝑔 ) ( 𝑤 ( +g ‘ 𝑔 ) 𝑥 )  =  ( 0g ‘ 𝑔 ) )  | 
						
						
							| 17 | 
							
								3 6 16
							 | 
							cmpt | 
							⊢ ( 𝑥  ∈  ( Base ‘ 𝑔 )  ↦  ( ℩ 𝑤  ∈  ( Base ‘ 𝑔 ) ( 𝑤 ( +g ‘ 𝑔 ) 𝑥 )  =  ( 0g ‘ 𝑔 ) ) )  | 
						
						
							| 18 | 
							
								1 2 17
							 | 
							cmpt | 
							⊢ ( 𝑔  ∈  V  ↦  ( 𝑥  ∈  ( Base ‘ 𝑔 )  ↦  ( ℩ 𝑤  ∈  ( Base ‘ 𝑔 ) ( 𝑤 ( +g ‘ 𝑔 ) 𝑥 )  =  ( 0g ‘ 𝑔 ) ) ) )  | 
						
						
							| 19 | 
							
								0 18
							 | 
							wceq | 
							⊢ invg  =  ( 𝑔  ∈  V  ↦  ( 𝑥  ∈  ( Base ‘ 𝑔 )  ↦  ( ℩ 𝑤  ∈  ( Base ‘ 𝑔 ) ( 𝑤 ( +g ‘ 𝑔 ) 𝑥 )  =  ( 0g ‘ 𝑔 ) ) ) )  |