| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fin23lem.a |  | 
						
							| 2 |  | unissb |  | 
						
							| 3 | 1 | fnseqom |  | 
						
							| 4 |  | fvelrnb |  | 
						
							| 5 | 3 4 | ax-mp |  | 
						
							| 6 |  | peano1 |  | 
						
							| 7 |  | 0ss |  | 
						
							| 8 | 1 | fin23lem15 |  | 
						
							| 9 | 7 8 | mpan2 |  | 
						
							| 10 | 6 9 | mpan2 |  | 
						
							| 11 |  | vex |  | 
						
							| 12 | 11 | rnex |  | 
						
							| 13 | 12 | uniex |  | 
						
							| 14 | 1 | seqom0g |  | 
						
							| 15 | 13 14 | ax-mp |  | 
						
							| 16 | 10 15 | sseqtrdi |  | 
						
							| 17 |  | sseq1 |  | 
						
							| 18 | 16 17 | syl5ibcom |  | 
						
							| 19 | 18 | rexlimiv |  | 
						
							| 20 | 5 19 | sylbi |  | 
						
							| 21 | 2 20 | mprgbir |  | 
						
							| 22 |  | fnfvelrn |  | 
						
							| 23 | 3 6 22 | mp2an |  | 
						
							| 24 | 15 23 | eqeltrri |  | 
						
							| 25 |  | elssuni |  | 
						
							| 26 | 24 25 | ax-mp |  | 
						
							| 27 | 21 26 | eqssi |  |