Metamath Proof Explorer


Theorem mdegaddle

Description: The degree of a sum is at most the maximum of the degrees of the factors. (Contributed by Stefan O'Rear, 26-Mar-2015)

Ref Expression
Hypotheses mdegaddle.y Y=ImPolyR
mdegaddle.d D=ImDegR
mdegaddle.i φIV
mdegaddle.r φRRing
mdegaddle.b B=BaseY
mdegaddle.p +˙=+Y
mdegaddle.f φFB
mdegaddle.g φGB
Assertion mdegaddle φDF+˙GifDFDGDGDF

Proof

Step Hyp Ref Expression
1 mdegaddle.y Y=ImPolyR
2 mdegaddle.d D=ImDegR
3 mdegaddle.i φIV
4 mdegaddle.r φRRing
5 mdegaddle.b B=BaseY
6 mdegaddle.p +˙=+Y
7 mdegaddle.f φFB
8 mdegaddle.g φGB
9 eqid +R=+R
10 1 5 9 6 7 8 mpladd φF+˙G=F+RfG
11 10 fveq1d φF+˙Gc=F+RfGc
12 11 adantr φca0I|a-1FinF+˙Gc=F+RfGc
13 eqid BaseR=BaseR
14 eqid a0I|a-1Fin=a0I|a-1Fin
15 1 13 5 14 7 mplelf φF:a0I|a-1FinBaseR
16 15 ffnd φFFna0I|a-1Fin
17 16 adantr φca0I|a-1FinFFna0I|a-1Fin
18 1 13 5 14 8 mplelf φG:a0I|a-1FinBaseR
19 18 ffnd φGFna0I|a-1Fin
20 19 adantr φca0I|a-1FinGFna0I|a-1Fin
21 ovex 0IV
22 21 rabex a0I|a-1FinV
23 22 a1i φca0I|a-1Fina0I|a-1FinV
24 simpr φca0I|a-1Finca0I|a-1Fin
25 fnfvof FFna0I|a-1FinGFna0I|a-1Fina0I|a-1FinVca0I|a-1FinF+RfGc=Fc+RGc
26 17 20 23 24 25 syl22anc φca0I|a-1FinF+RfGc=Fc+RGc
27 12 26 eqtrd φca0I|a-1FinF+˙Gc=Fc+RGc
28 27 adantrr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcF+˙Gc=Fc+RGc
29 eqid 0R=0R
30 eqid ba0I|a-1Finfldb=ba0I|a-1Finfldb
31 7 adantr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcFB
32 simprl φca0I|a-1FinifDFDGDGDF<ba0I|a-1Finfldbcca0I|a-1Fin
33 2 1 5 mdegxrcl FBDF*
34 7 33 syl φDF*
35 34 adantr φca0I|a-1FinDF*
36 2 1 5 mdegxrcl GBDG*
37 8 36 syl φDG*
38 37 34 ifcld φifDFDGDGDF*
39 38 adantr φca0I|a-1FinifDFDGDGDF*
40 nn0ssre 0
41 ressxr *
42 40 41 sstri 0*
43 14 30 tdeglem1 ba0I|a-1Finfldb:a0I|a-1Fin0
44 43 a1i φba0I|a-1Finfldb:a0I|a-1Fin0
45 44 ffvelcdmda φca0I|a-1Finba0I|a-1Finfldbc0
46 42 45 sselid φca0I|a-1Finba0I|a-1Finfldbc*
47 35 39 46 3jca φca0I|a-1FinDF*ifDFDGDGDF*ba0I|a-1Finfldbc*
48 47 adantrr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDF*ifDFDGDGDF*ba0I|a-1Finfldbc*
49 xrmax1 DF*DG*DFifDFDGDGDF
50 34 37 49 syl2anc φDFifDFDGDGDF
51 50 adantr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDFifDFDGDGDF
52 simprr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcifDFDGDGDF<ba0I|a-1Finfldbc
53 51 52 jca φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDFifDFDGDGDFifDFDGDGDF<ba0I|a-1Finfldbc
54 xrlelttr DF*ifDFDGDGDF*ba0I|a-1Finfldbc*DFifDFDGDGDFifDFDGDGDF<ba0I|a-1FinfldbcDF<ba0I|a-1Finfldbc
55 48 53 54 sylc φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDF<ba0I|a-1Finfldbc
56 2 1 5 29 14 30 31 32 55 mdeglt φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcFc=0R
57 8 adantr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcGB
58 37 adantr φca0I|a-1FinDG*
59 58 39 46 3jca φca0I|a-1FinDG*ifDFDGDGDF*ba0I|a-1Finfldbc*
60 59 adantrr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDG*ifDFDGDGDF*ba0I|a-1Finfldbc*
61 xrmax2 DF*DG*DGifDFDGDGDF
62 34 37 61 syl2anc φDGifDFDGDGDF
63 62 adantr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDGifDFDGDGDF
64 63 52 jca φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDGifDFDGDGDFifDFDGDGDF<ba0I|a-1Finfldbc
65 xrlelttr DG*ifDFDGDGDF*ba0I|a-1Finfldbc*DGifDFDGDGDFifDFDGDGDF<ba0I|a-1FinfldbcDG<ba0I|a-1Finfldbc
66 60 64 65 sylc φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcDG<ba0I|a-1Finfldbc
67 2 1 5 29 14 30 57 32 66 mdeglt φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcGc=0R
68 56 67 oveq12d φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcFc+RGc=0R+R0R
69 ringgrp RRingRGrp
70 4 69 syl φRGrp
71 13 29 ring0cl RRing0RBaseR
72 4 71 syl φ0RBaseR
73 13 9 29 grplid RGrp0RBaseR0R+R0R=0R
74 70 72 73 syl2anc φ0R+R0R=0R
75 74 adantr φca0I|a-1FinifDFDGDGDF<ba0I|a-1Finfldbc0R+R0R=0R
76 68 75 eqtrd φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcFc+RGc=0R
77 28 76 eqtrd φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcF+˙Gc=0R
78 77 expr φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcF+˙Gc=0R
79 78 ralrimiva φca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcF+˙Gc=0R
80 1 mplring IVRRingYRing
81 3 4 80 syl2anc φYRing
82 5 6 ringacl YRingFBGBF+˙GB
83 81 7 8 82 syl3anc φF+˙GB
84 2 1 5 29 14 30 mdegleb F+˙GBifDFDGDGDF*DF+˙GifDFDGDGDFca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcF+˙Gc=0R
85 83 38 84 syl2anc φDF+˙GifDFDGDGDFca0I|a-1FinifDFDGDGDF<ba0I|a-1FinfldbcF+˙Gc=0R
86 79 85 mpbird φDF+˙GifDFDGDGDF