| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sadval.a |  | 
						
							| 2 |  | sadval.b |  | 
						
							| 3 |  | sadval.c |  | 
						
							| 4 |  | sadcp1.n |  | 
						
							| 5 |  | sadcadd.k |  | 
						
							| 6 |  | 2nn |  | 
						
							| 7 | 6 | a1i |  | 
						
							| 8 | 7 4 | nnexpcld |  | 
						
							| 9 | 8 | nnzd |  | 
						
							| 10 |  | iddvds |  | 
						
							| 11 | 9 10 | syl |  | 
						
							| 12 |  | dvds0 |  | 
						
							| 13 | 9 12 | syl |  | 
						
							| 14 |  | breq2 |  | 
						
							| 15 |  | breq2 |  | 
						
							| 16 | 14 15 | ifboth |  | 
						
							| 17 | 11 13 16 | syl2anc |  | 
						
							| 18 |  | inss1 |  | 
						
							| 19 | 1 2 3 | sadfval |  | 
						
							| 20 |  | ssrab2 |  | 
						
							| 21 | 19 20 | eqsstrdi |  | 
						
							| 22 | 18 21 | sstrid |  | 
						
							| 23 |  | fzofi |  | 
						
							| 24 | 23 | a1i |  | 
						
							| 25 |  | inss2 |  | 
						
							| 26 |  | ssfi |  | 
						
							| 27 | 24 25 26 | sylancl |  | 
						
							| 28 |  | elfpw |  | 
						
							| 29 | 22 27 28 | sylanbrc |  | 
						
							| 30 |  | bitsf1o |  | 
						
							| 31 |  | f1ocnv |  | 
						
							| 32 |  | f1of |  | 
						
							| 33 | 30 31 32 | mp2b |  | 
						
							| 34 | 5 | feq1i |  | 
						
							| 35 | 33 34 | mpbir |  | 
						
							| 36 | 35 | ffvelcdmi |  | 
						
							| 37 | 29 36 | syl |  | 
						
							| 38 | 37 | nn0cnd |  | 
						
							| 39 | 8 | nncnd |  | 
						
							| 40 |  | 0cn |  | 
						
							| 41 |  | ifcl |  | 
						
							| 42 | 39 40 41 | sylancl |  | 
						
							| 43 | 38 42 | pncan2d |  | 
						
							| 44 | 17 43 | breqtrrd |  | 
						
							| 45 | 37 | nn0zd |  | 
						
							| 46 | 9 | adantr |  | 
						
							| 47 |  | 0zd |  | 
						
							| 48 | 46 47 | ifclda |  | 
						
							| 49 | 45 48 | zaddcld |  | 
						
							| 50 |  | moddvds |  | 
						
							| 51 | 8 49 45 50 | syl3anc |  | 
						
							| 52 | 44 51 | mpbird |  | 
						
							| 53 | 1 2 3 4 5 | sadadd2 |  | 
						
							| 54 | 53 | oveq1d |  | 
						
							| 55 | 52 54 | eqtr3d |  |