| Step | Hyp | Ref | Expression | 
						
							| 1 |  | decpmatmul.p |  | 
						
							| 2 |  | decpmatmul.c |  | 
						
							| 3 |  | decpmatmul.b |  | 
						
							| 4 |  | decpmatmul.a |  | 
						
							| 5 |  | decpmatmulsumfsupp.m |  | 
						
							| 6 |  | decpmatmulsumfsupp.0 |  | 
						
							| 7 | 6 | fvexi |  | 
						
							| 8 | 7 | a1i |  | 
						
							| 9 |  | ovexd |  | 
						
							| 10 |  | oveq2 |  | 
						
							| 11 |  | oveq1 |  | 
						
							| 12 | 11 | oveq2d |  | 
						
							| 13 | 12 | oveq2d |  | 
						
							| 14 | 10 13 | mpteq12dv |  | 
						
							| 15 | 14 | oveq2d |  | 
						
							| 16 |  | simpll |  | 
						
							| 17 |  | simplr |  | 
						
							| 18 | 1 2 | pmatring |  | 
						
							| 19 | 18 | anim1i |  | 
						
							| 20 |  | 3anass |  | 
						
							| 21 | 19 20 | sylibr |  | 
						
							| 22 |  | eqid |  | 
						
							| 23 | 3 22 | ringcl |  | 
						
							| 24 | 21 23 | syl |  | 
						
							| 25 |  | eqid |  | 
						
							| 26 | 1 2 3 25 | pmatcoe1fsupp |  | 
						
							| 27 | 16 17 24 26 | syl3anc |  | 
						
							| 28 |  | fvoveq1 |  | 
						
							| 29 | 28 | fveq1d |  | 
						
							| 30 | 29 | eqeq1d |  | 
						
							| 31 |  | oveq2 |  | 
						
							| 32 | 31 | fveq2d |  | 
						
							| 33 | 32 | fveq1d |  | 
						
							| 34 | 33 | eqeq1d |  | 
						
							| 35 | 30 34 | rspc2va |  | 
						
							| 36 | 35 | expcom |  | 
						
							| 37 | 36 | adantl |  | 
						
							| 38 | 37 | 3impib |  | 
						
							| 39 | 38 | mpoeq3dva |  | 
						
							| 40 | 4 25 | mat0op |  | 
						
							| 41 | 6 40 | eqtrid |  | 
						
							| 42 | 41 | ad3antrrr |  | 
						
							| 43 | 39 42 | eqtr4d |  | 
						
							| 44 | 43 | ex |  | 
						
							| 45 | 44 | imim2d |  | 
						
							| 46 | 45 | ralimdva |  | 
						
							| 47 | 46 | reximdv |  | 
						
							| 48 | 27 47 | mpd |  | 
						
							| 49 | 5 | oveqi |  | 
						
							| 50 | 49 | a1i |  | 
						
							| 51 | 50 | mpteq2dv |  | 
						
							| 52 | 51 | oveq2d |  | 
						
							| 53 | 1 2 3 4 | decpmatmul |  | 
						
							| 54 | 53 | ad4ant234 |  | 
						
							| 55 | 2 3 | decpmatval |  | 
						
							| 56 | 24 55 | sylan |  | 
						
							| 57 | 52 54 56 | 3eqtr2d |  | 
						
							| 58 | 57 | eqeq1d |  | 
						
							| 59 | 58 | imbi2d |  | 
						
							| 60 | 59 | ralbidva |  | 
						
							| 61 | 60 | rexbidv |  | 
						
							| 62 | 48 61 | mpbird |  | 
						
							| 63 | 8 9 15 62 | mptnn0fsuppd |  |