| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cnfcom3c |  | 
						
							| 2 |  | df-2o |  | 
						
							| 3 | 2 | oveq2i |  | 
						
							| 4 |  | omelon |  | 
						
							| 5 |  | 1on |  | 
						
							| 6 |  | oesuc |  | 
						
							| 7 | 4 5 6 | mp2an |  | 
						
							| 8 |  | oe1 |  | 
						
							| 9 | 4 8 | ax-mp |  | 
						
							| 10 | 9 | oveq1i |  | 
						
							| 11 | 3 7 10 | 3eqtri |  | 
						
							| 12 |  | omxpen |  | 
						
							| 13 | 4 4 12 | mp2an |  | 
						
							| 14 | 11 13 | eqbrtri |  | 
						
							| 15 |  | xpomen |  | 
						
							| 16 | 14 15 | entri |  | 
						
							| 17 | 16 | a1i |  | 
						
							| 18 |  | bren |  | 
						
							| 19 | 17 18 | sylib |  | 
						
							| 20 |  | exdistrv |  | 
						
							| 21 |  | simpl |  | 
						
							| 22 |  | simprl |  | 
						
							| 23 |  | sseq2 |  | 
						
							| 24 |  | oveq2 |  | 
						
							| 25 | 24 | f1oeq3d |  | 
						
							| 26 | 25 | cbvrexvw |  | 
						
							| 27 |  | fveq2 |  | 
						
							| 28 | 27 | f1oeq1d |  | 
						
							| 29 |  | f1oeq2 |  | 
						
							| 30 | 28 29 | bitrd |  | 
						
							| 31 | 30 | rexbidv |  | 
						
							| 32 | 26 31 | bitrid |  | 
						
							| 33 | 23 32 | imbi12d |  | 
						
							| 34 | 33 | cbvralvw |  | 
						
							| 35 | 22 34 | sylib |  | 
						
							| 36 |  | oveq2 |  | 
						
							| 37 | 36 | cbvmptv |  | 
						
							| 38 | 37 | cnveqi |  | 
						
							| 39 | 38 | fveq1i |  | 
						
							| 40 |  | 2on |  | 
						
							| 41 |  | peano1 |  | 
						
							| 42 |  | oen0 |  | 
						
							| 43 | 41 42 | mpan2 |  | 
						
							| 44 | 4 40 43 | mp2an |  | 
						
							| 45 |  | eqid |  | 
						
							| 46 | 45 | fveqf1o |  | 
						
							| 47 | 44 41 46 | mp3an23 |  | 
						
							| 48 | 47 | ad2antll |  | 
						
							| 49 | 48 | simpld |  | 
						
							| 50 | 48 | simprd |  | 
						
							| 51 | 21 35 39 49 50 | infxpenc2lem3 |  | 
						
							| 52 | 51 | ex |  | 
						
							| 53 | 52 | exlimdvv |  | 
						
							| 54 | 20 53 | biimtrrid |  | 
						
							| 55 | 1 19 54 | mp2and |  |