| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sseqval.1 |  | 
						
							| 2 |  | sseqval.2 |  | 
						
							| 3 |  | sseqval.3 |  | 
						
							| 4 |  | sseqval.4 |  | 
						
							| 5 |  | df-sseq |  | 
						
							| 6 | 5 | a1i |  | 
						
							| 7 |  | simprl |  | 
						
							| 8 | 7 | fveq2d |  | 
						
							| 9 |  | simp1rr |  | 
						
							| 10 | 9 | fveq1d |  | 
						
							| 11 | 10 | s1eqd |  | 
						
							| 12 | 11 | oveq2d |  | 
						
							| 13 | 12 | mpoeq3dva |  | 
						
							| 14 |  | simprr |  | 
						
							| 15 | 14 7 | fveq12d |  | 
						
							| 16 | 15 | s1eqd |  | 
						
							| 17 | 7 16 | oveq12d |  | 
						
							| 18 | 17 | sneqd |  | 
						
							| 19 | 18 | xpeq2d |  | 
						
							| 20 | 8 13 19 | seqeq123d |  | 
						
							| 21 | 20 | coeq2d |  | 
						
							| 22 | 7 21 | uneq12d |  | 
						
							| 23 |  | elex |  | 
						
							| 24 | 2 23 | syl |  | 
						
							| 25 |  | wrdexg |  | 
						
							| 26 |  | inex1g |  | 
						
							| 27 | 1 25 26 | 3syl |  | 
						
							| 28 | 3 27 | eqeltrid |  | 
						
							| 29 | 4 28 | fexd |  | 
						
							| 30 |  | df-lsw |  | 
						
							| 31 | 30 | funmpt2 |  | 
						
							| 32 | 31 | a1i |  | 
						
							| 33 |  | seqex |  | 
						
							| 34 | 33 | a1i |  | 
						
							| 35 |  | cofunexg |  | 
						
							| 36 | 32 34 35 | syl2anc |  | 
						
							| 37 |  | unexg |  | 
						
							| 38 | 24 36 37 | syl2anc |  | 
						
							| 39 | 6 22 24 29 38 | ovmpod |  |