| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oveq2 |  | 
						
							| 2 | 1 | iuneq2d |  | 
						
							| 3 |  | oveq2 |  | 
						
							| 4 | 2 3 | sseq12d |  | 
						
							| 5 |  | oveq2 |  | 
						
							| 6 | 5 | iuneq2d |  | 
						
							| 7 |  | oveq2 |  | 
						
							| 8 | 6 7 | sseq12d |  | 
						
							| 9 |  | oveq2 |  | 
						
							| 10 | 9 | iuneq2d |  | 
						
							| 11 |  | oveq2 |  | 
						
							| 12 | 10 11 | sseq12d |  | 
						
							| 13 |  | oveq2 |  | 
						
							| 14 | 13 | iuneq2d |  | 
						
							| 15 |  | oveq2 |  | 
						
							| 16 | 14 15 | sseq12d |  | 
						
							| 17 |  | oveq2 |  | 
						
							| 18 | 17 | cbviunv |  | 
						
							| 19 |  | oveq2 |  | 
						
							| 20 | 19 | cbviunv |  | 
						
							| 21 | 18 20 | eqtri |  | 
						
							| 22 |  | ovex |  | 
						
							| 23 |  | relexp1g |  | 
						
							| 24 | 22 23 | mp1i |  | 
						
							| 25 | 24 | iuneq2i |  | 
						
							| 26 |  | nnex |  | 
						
							| 27 |  | ovex |  | 
						
							| 28 | 26 27 | iunex |  | 
						
							| 29 |  | relexp1g |  | 
						
							| 30 | 28 29 | ax-mp |  | 
						
							| 31 | 21 25 30 | 3eqtr4i |  | 
						
							| 32 | 31 | eqimssi |  | 
						
							| 33 |  | oveq2 |  | 
						
							| 34 | 33 | oveq1d |  | 
						
							| 35 | 34 33 | coeq12d |  | 
						
							| 36 | 35 | cbviunv |  | 
						
							| 37 |  | ss2iun |  | 
						
							| 38 | 34 | ssiun2s |  | 
						
							| 39 |  | coss1 |  | 
						
							| 40 | 38 39 | syl |  | 
						
							| 41 | 37 40 | mprg |  | 
						
							| 42 | 36 41 | eqsstri |  | 
						
							| 43 |  | coss1 |  | 
						
							| 44 | 43 | ralrimivw |  | 
						
							| 45 |  | ss2iun |  | 
						
							| 46 | 44 45 | syl |  | 
						
							| 47 | 42 46 | sstrid |  | 
						
							| 48 | 47 | adantl |  | 
						
							| 49 |  | relexpsucnnr |  | 
						
							| 50 | 22 49 | mpan |  | 
						
							| 51 | 50 | iuneq2d |  | 
						
							| 52 | 51 | adantr |  | 
						
							| 53 |  | relexpsucnnr |  | 
						
							| 54 | 28 53 | mpan |  | 
						
							| 55 |  | oveq2 |  | 
						
							| 56 | 55 | cbviunv |  | 
						
							| 57 | 56 | coeq2i |  | 
						
							| 58 |  | coiun |  | 
						
							| 59 | 57 58 | eqtri |  | 
						
							| 60 | 54 59 | eqtrdi |  | 
						
							| 61 | 60 | adantr |  | 
						
							| 62 | 48 52 61 | 3sstr4d |  | 
						
							| 63 | 62 | ex |  | 
						
							| 64 | 4 8 12 16 32 63 | nnind |  |