| Step | Hyp | Ref | Expression | 
						
							| 1 |  | infxpenc2.1 |  | 
						
							| 2 |  | infxpenc2.2 |  | 
						
							| 3 |  | infxpenc2.3 |  | 
						
							| 4 | 2 | r19.21bi |  | 
						
							| 5 | 4 | impr |  | 
						
							| 6 |  | simpr |  | 
						
							| 7 |  | oveq2 |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 |  | ovex |  | 
						
							| 10 | 7 8 9 | fvmpt |  | 
						
							| 11 | 10 | ad2antrl |  | 
						
							| 12 |  | f1ofo |  | 
						
							| 13 | 12 | ad2antll |  | 
						
							| 14 |  | forn |  | 
						
							| 15 | 13 14 | syl |  | 
						
							| 16 | 11 15 | eqtr4d |  | 
						
							| 17 |  | ovex |  | 
						
							| 18 | 17 | 2a1i |  | 
						
							| 19 |  | omelon |  | 
						
							| 20 |  | 1onn |  | 
						
							| 21 |  | ondif2 |  | 
						
							| 22 | 19 20 21 | mpbir2an |  | 
						
							| 23 |  | eldifi |  | 
						
							| 24 | 23 | ad2antrl |  | 
						
							| 25 |  | eldifi |  | 
						
							| 26 | 25 | ad2antll |  | 
						
							| 27 |  | oecan |  | 
						
							| 28 | 22 24 26 27 | mp3an2i |  | 
						
							| 29 | 28 | ex |  | 
						
							| 30 | 18 29 | dom2lem |  | 
						
							| 31 |  | f1f1orn |  | 
						
							| 32 | 30 31 | syl |  | 
						
							| 33 |  | simprl |  | 
						
							| 34 |  | f1ocnvfv |  | 
						
							| 35 | 32 33 34 | syl2anc |  | 
						
							| 36 | 16 35 | mpd |  | 
						
							| 37 | 3 36 | eqtrid |  | 
						
							| 38 | 37 | eleq1d |  | 
						
							| 39 | 37 | oveq2d |  | 
						
							| 40 | 39 | f1oeq3d |  | 
						
							| 41 | 38 40 | anbi12d |  | 
						
							| 42 | 6 41 | mpbird |  | 
						
							| 43 | 5 42 | rexlimddv |  |