Metamath Proof Explorer


Theorem mpomatmul

Description: Multiplication of two N x N matrices given in maps-to notation. (Contributed by AV, 29-Oct-2019)

Ref Expression
Hypotheses mpomatmul.a A=NMatR
mpomatmul.b B=BaseR
mpomatmul.m ×˙=A
mpomatmul.t ·˙=R
mpomatmul.r φRV
mpomatmul.n φNFin
mpomatmul.x X=iN,jNC
mpomatmul.y Y=iN,jNE
mpomatmul.c φiNjNCB
mpomatmul.e φiNjNEB
mpomatmul.d φk=im=jD=C
mpomatmul.f φm=il=jF=E
mpomatmul.1 φkNmNDU
mpomatmul.2 φmNlNFW
Assertion mpomatmul φX×˙Y=kN,lNRmND·˙F

Proof

Step Hyp Ref Expression
1 mpomatmul.a A=NMatR
2 mpomatmul.b B=BaseR
3 mpomatmul.m ×˙=A
4 mpomatmul.t ·˙=R
5 mpomatmul.r φRV
6 mpomatmul.n φNFin
7 mpomatmul.x X=iN,jNC
8 mpomatmul.y Y=iN,jNE
9 mpomatmul.c φiNjNCB
10 mpomatmul.e φiNjNEB
11 mpomatmul.d φk=im=jD=C
12 mpomatmul.f φm=il=jF=E
13 mpomatmul.1 φkNmNDU
14 mpomatmul.2 φmNlNFW
15 eqid RmaMulNNN=RmaMulNNN
16 1 15 matmulr NFinRVRmaMulNNN=A
17 16 3 eqtr4di NFinRVRmaMulNNN=×˙
18 17 oveqd NFinRVXRmaMulNNNY=X×˙Y
19 18 eqcomd NFinRVX×˙Y=XRmaMulNNNY
20 6 5 19 syl2anc φX×˙Y=XRmaMulNNNY
21 eqid BaseR=BaseR
22 eqid BaseA=BaseA
23 9 2 eleqtrdi φiNjNCBaseR
24 1 21 22 6 5 23 matbas2d φiN,jNCBaseA
25 7 24 eqeltrid φXBaseA
26 1 21 matbas2 NFinRVBaseRN×N=BaseA
27 6 5 26 syl2anc φBaseRN×N=BaseA
28 25 27 eleqtrrd φXBaseRN×N
29 10 2 eleqtrdi φiNjNEBaseR
30 1 21 22 6 5 29 matbas2d φiN,jNEBaseA
31 8 30 eqeltrid φYBaseA
32 31 27 eleqtrrd φYBaseRN×N
33 15 21 4 5 6 6 6 28 32 mamuval φXRmaMulNNNY=kN,lNRmNkXm·˙mYl
34 7 a1i φkNlNmNX=iN,jNC
35 equcom i=kk=i
36 equcom j=mm=j
37 35 36 anbi12i i=kj=mk=im=j
38 37 11 sylan2b φi=kj=mD=C
39 38 eqcomd φi=kj=mC=D
40 39 ex φi=kj=mC=D
41 40 3ad2ant1 φkNlNi=kj=mC=D
42 41 adantr φkNlNmNi=kj=mC=D
43 42 imp φkNlNmNi=kj=mC=D
44 simpl2 φkNlNmNkN
45 simpr φkNlNmNmN
46 simpl1 φkNlNmNφ
47 46 44 45 13 syl3anc φkNlNmNDU
48 34 43 44 45 47 ovmpod φkNlNmNkXm=D
49 8 a1i φkNlNmNY=iN,jNE
50 equcomi i=mm=i
51 equcomi j=ll=j
52 50 51 anim12i i=mj=lm=il=j
53 52 12 sylan2 φi=mj=lF=E
54 53 ex φi=mj=lF=E
55 54 3ad2ant1 φkNlNi=mj=lF=E
56 55 adantr φkNlNmNi=mj=lF=E
57 56 imp φkNlNmNi=mj=lF=E
58 57 eqcomd φkNlNmNi=mj=lE=F
59 simpl3 φkNlNmNlN
60 46 45 59 14 syl3anc φkNlNmNFW
61 49 58 45 59 60 ovmpod φkNlNmNmYl=F
62 48 61 oveq12d φkNlNmNkXm·˙mYl=D·˙F
63 62 mpteq2dva φkNlNmNkXm·˙mYl=mND·˙F
64 63 oveq2d φkNlNRmNkXm·˙mYl=RmND·˙F
65 64 mpoeq3dva φkN,lNRmNkXm·˙mYl=kN,lNRmND·˙F
66 20 33 65 3eqtrd φX×˙Y=kN,lNRmND·˙F