| Step | Hyp | Ref | Expression | 
						
							| 1 |  | alephfplem.1 |  | 
						
							| 2 |  | frfnom |  | 
						
							| 3 | 1 | fneq1i |  | 
						
							| 4 | 2 3 | mpbir |  | 
						
							| 5 | 1 | alephfplem3 |  | 
						
							| 6 | 5 | rgen |  | 
						
							| 7 |  | ffnfv |  | 
						
							| 8 | 4 6 7 | mpbir2an |  | 
						
							| 9 |  | ssun2 |  | 
						
							| 10 |  | fss |  | 
						
							| 11 | 8 9 10 | mp2an |  | 
						
							| 12 |  | peano1 |  | 
						
							| 13 | 1 | alephfplem1 |  | 
						
							| 14 |  | fveq2 |  | 
						
							| 15 | 14 | eleq1d |  | 
						
							| 16 | 15 | rspcev |  | 
						
							| 17 | 12 13 16 | mp2an |  | 
						
							| 18 |  | omex |  | 
						
							| 19 |  | cardinfima |  | 
						
							| 20 | 18 19 | ax-mp |  | 
						
							| 21 | 11 17 20 | mp2an |  |