Metamath Proof Explorer


Theorem selvply1rhm0

Description: The ring homomorphism H built in selvply1rhm is injective. (Contributed by Thierry Arnoux, 4-May-2026)

Ref Expression
Hypotheses selvply1rhm.1 𝐵 = ( Base ‘ 𝑃 )
selvply1rhm.2 𝑃 = ( 𝐼 mPoly 𝑅 )
selvply1rhm.3 𝑈 = ( ( 𝐼 ∖ { 𝑋 } ) mPoly 𝑅 )
selvply1rhm.4 𝑄 = ( Poly1𝑈 )
selvply1rhm.5 𝐻 = ( 𝑓𝐵 ↦ ( 𝑛 ∈ ( ℕ0m 1o ) ↦ ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝑓 ) ‘ { ⟨ 𝑋 , ( 𝑛 ‘ ∅ ) ⟩ } ) ) )
selvply1rhm.6 ( 𝜑𝐼𝑉 )
selvply1rhm.7 ( 𝜑𝑋𝐼 )
selvply1rhm.8 ( 𝜑𝑅 ∈ CRing )
selvply1rhm0.1 0 = ( 0g𝑄 )
selvply1rhm0.2 𝑍 = ( 0g𝑃 )
selvply1rhm0.3 ( 𝜑𝐹𝐵 )
selvply1rhm0.4 ( 𝜑 → ( 𝐻𝐹 ) = 0 )
Assertion selvply1rhm0 ( 𝜑𝐹 = 𝑍 )

Proof

Step Hyp Ref Expression
1 selvply1rhm.1 𝐵 = ( Base ‘ 𝑃 )
2 selvply1rhm.2 𝑃 = ( 𝐼 mPoly 𝑅 )
3 selvply1rhm.3 𝑈 = ( ( 𝐼 ∖ { 𝑋 } ) mPoly 𝑅 )
4 selvply1rhm.4 𝑄 = ( Poly1𝑈 )
5 selvply1rhm.5 𝐻 = ( 𝑓𝐵 ↦ ( 𝑛 ∈ ( ℕ0m 1o ) ↦ ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝑓 ) ‘ { ⟨ 𝑋 , ( 𝑛 ‘ ∅ ) ⟩ } ) ) )
6 selvply1rhm.6 ( 𝜑𝐼𝑉 )
7 selvply1rhm.7 ( 𝜑𝑋𝐼 )
8 selvply1rhm.8 ( 𝜑𝑅 ∈ CRing )
9 selvply1rhm0.1 0 = ( 0g𝑄 )
10 selvply1rhm0.2 𝑍 = ( 0g𝑃 )
11 selvply1rhm0.3 ( 𝜑𝐹𝐵 )
12 selvply1rhm0.4 ( 𝜑 → ( 𝐻𝐹 ) = 0 )
13 eqid ( Base ‘ 𝑅 ) = ( Base ‘ 𝑅 )
14 eqid { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } = { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 }
15 14 psrbasfsupp { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } = { ∈ ( ℕ0m 𝐼 ) ∣ ( “ ℕ ) ∈ Fin }
16 2 13 1 15 11 mplelf ( 𝜑𝐹 : { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ⟶ ( Base ‘ 𝑅 ) )
17 16 feqmptd ( 𝜑𝐹 = ( 𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ↦ ( 𝐹𝑝 ) ) )
18 nn0ex 0 ∈ V
19 18 a1i ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ℕ0 ∈ V )
20 1oex 1o ∈ V
21 20 a1i ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 1o ∈ V )
22 df1o2 1o = { ∅ }
23 22 eqcomi { ∅ } = 1o
24 23 a1i ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → { ∅ } = 1o )
25 0ex ∅ ∈ V
26 25 a1i ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ∅ ∈ V )
27 6 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝐼𝑉 )
28 ssrab2 { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ⊆ ( ℕ0m 𝐼 )
29 28 a1i ( 𝜑 → { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ⊆ ( ℕ0m 𝐼 ) )
30 29 sselda ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑝 ∈ ( ℕ0m 𝐼 ) )
31 27 19 30 elmaprd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑝 : 𝐼 ⟶ ℕ0 )
32 7 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑋𝐼 )
33 31 32 ffvelcdmd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝑝𝑋 ) ∈ ℕ0 )
34 26 33 fsnd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } : { ∅ } ⟶ ℕ0 )
35 24 34 feq2dd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } : 1o ⟶ ℕ0 )
36 19 21 35 elmapdd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ∈ ( ℕ0m 1o ) )
37 psr1baslem ( ℕ0m 1o ) = { ∈ ( ℕ0m 1o ) ∣ ( “ ℕ ) ∈ Fin }
38 eqid { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } = { ∈ ( ℕ0m 1o ) ∣ finSupp 0 }
39 38 psrbasfsupp { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } = { ∈ ( ℕ0m 1o ) ∣ ( “ ℕ ) ∈ Fin }
40 37 39 eqtr4i ( ℕ0m 1o ) = { ∈ ( ℕ0m 1o ) ∣ finSupp 0 }
41 36 40 eleqtrdi ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ∈ { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } )
42 fvex ( 0g𝑈 ) ∈ V
43 42 fvconst2 ( { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ∈ { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } → ( ( { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } × { ( 0g𝑈 ) } ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) = ( 0g𝑈 ) )
44 41 43 syl ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } × { ( 0g𝑈 ) } ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) = ( 0g𝑈 ) )
45 31 ffnd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑝 Fn 𝐼 )
46 fnressn ( ( 𝑝 Fn 𝐼𝑋𝐼 ) → ( 𝑝 ↾ { 𝑋 } ) = { ⟨ 𝑋 , ( 𝑝𝑋 ) ⟩ } )
47 45 32 46 syl2anc ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝑝 ↾ { 𝑋 } ) = { ⟨ 𝑋 , ( 𝑝𝑋 ) ⟩ } )
48 fvex ( 𝑝𝑋 ) ∈ V
49 25 48 fvsn ( { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ‘ ∅ ) = ( 𝑝𝑋 )
50 49 opeq2i 𝑋 , ( { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ‘ ∅ ) ⟩ = ⟨ 𝑋 , ( 𝑝𝑋 ) ⟩
51 50 sneqi { ⟨ 𝑋 , ( { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ‘ ∅ ) ⟩ } = { ⟨ 𝑋 , ( 𝑝𝑋 ) ⟩ }
52 47 51 eqtr4di ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝑝 ↾ { 𝑋 } ) = { ⟨ 𝑋 , ( { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ‘ ∅ ) ⟩ } )
53 52 fveq2d ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝐹 ) ‘ ( 𝑝 ↾ { 𝑋 } ) ) = ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝐹 ) ‘ { ⟨ 𝑋 , ( { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ‘ ∅ ) ⟩ } ) )
54 8 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑅 ∈ CRing )
55 11 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝐹𝐵 )
56 1 2 3 4 5 27 32 54 55 36 selvply1rhmlem3 ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( 𝐻𝐹 ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) = ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝐹 ) ‘ { ⟨ 𝑋 , ( { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ‘ ∅ ) ⟩ } ) )
57 eqid ( 1o mPoly 𝑈 ) = ( 1o mPoly 𝑈 )
58 eqid ( 0g𝑈 ) = ( 0g𝑈 )
59 57 4 9 ply1mpl0 0 = ( 0g ‘ ( 1o mPoly 𝑈 ) )
60 20 a1i ( 𝜑 → 1o ∈ V )
61 6 difexd ( 𝜑 → ( 𝐼 ∖ { 𝑋 } ) ∈ V )
62 8 crngringd ( 𝜑𝑅 ∈ Ring )
63 3 61 62 mplringd ( 𝜑𝑈 ∈ Ring )
64 63 ringgrpd ( 𝜑𝑈 ∈ Grp )
65 57 39 58 59 60 64 mpl0 ( 𝜑0 = ( { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } × { ( 0g𝑈 ) } ) )
66 12 65 eqtrd ( 𝜑 → ( 𝐻𝐹 ) = ( { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } × { ( 0g𝑈 ) } ) )
67 66 fveq1d ( 𝜑 → ( ( 𝐻𝐹 ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) = ( ( { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } × { ( 0g𝑈 ) } ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) )
68 67 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( 𝐻𝐹 ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) = ( ( { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } × { ( 0g𝑈 ) } ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) )
69 53 56 68 3eqtr2rd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( { ∈ ( ℕ0m 1o ) ∣ finSupp 0 } × { ( 0g𝑈 ) } ) ‘ { ⟨ ∅ , ( 𝑝𝑋 ) ⟩ } ) = ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝐹 ) ‘ ( 𝑝 ↾ { 𝑋 } ) ) )
70 eqid { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } = { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 }
71 70 psrbasfsupp { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } = { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ ( “ ℕ ) ∈ Fin }
72 eqid ( 0g𝑅 ) = ( 0g𝑅 )
73 61 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝐼 ∖ { 𝑋 } ) ∈ V )
74 62 ringgrpd ( 𝜑𝑅 ∈ Grp )
75 74 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑅 ∈ Grp )
76 3 71 72 58 73 75 mpl0 ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 0g𝑈 ) = ( { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } × { ( 0g𝑅 ) } ) )
77 44 69 76 3eqtr3d ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝐹 ) ‘ ( 𝑝 ↾ { 𝑋 } ) ) = ( { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } × { ( 0g𝑅 ) } ) )
78 77 fveq1d ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝐹 ) ‘ ( 𝑝 ↾ { 𝑋 } ) ) ‘ ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ) = ( ( { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } × { ( 0g𝑅 ) } ) ‘ ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ) )
79 7 snssd ( 𝜑 → { 𝑋 } ⊆ 𝐼 )
80 79 adantr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → { 𝑋 } ⊆ 𝐼 )
81 simpr ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } )
82 15 2 1 54 80 55 81 selvvvval ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( ( ( ( 𝐼 selectVars 𝑅 ) ‘ { 𝑋 } ) ‘ 𝐹 ) ‘ ( 𝑝 ↾ { 𝑋 } ) ) ‘ ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ) = ( 𝐹𝑝 ) )
83 breq1 ( = ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) → ( finSupp 0 ↔ ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) finSupp 0 ) )
84 difssd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝐼 ∖ { 𝑋 } ) ⊆ 𝐼 )
85 30 84 elmapssresd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) )
86 breq1 ( = 𝑝 → ( finSupp 0 ↔ 𝑝 finSupp 0 ) )
87 86 81 elrabrd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 𝑝 finSupp 0 )
88 c0ex 0 ∈ V
89 88 a1i ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → 0 ∈ V )
90 87 89 fsuppres ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) finSupp 0 )
91 83 85 90 elrabd ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ∈ { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } )
92 fvex ( 0g𝑅 ) ∈ V
93 92 fvconst2 ( ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ∈ { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } → ( ( { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } × { ( 0g𝑅 ) } ) ‘ ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ) = ( 0g𝑅 ) )
94 91 93 syl ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( ( { ∈ ( ℕ0m ( 𝐼 ∖ { 𝑋 } ) ) ∣ finSupp 0 } × { ( 0g𝑅 ) } ) ‘ ( 𝑝 ↾ ( 𝐼 ∖ { 𝑋 } ) ) ) = ( 0g𝑅 ) )
95 78 82 94 3eqtr3d ( ( 𝜑𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ) → ( 𝐹𝑝 ) = ( 0g𝑅 ) )
96 95 mpteq2dva ( 𝜑 → ( 𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ↦ ( 𝐹𝑝 ) ) = ( 𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ↦ ( 0g𝑅 ) ) )
97 2 15 72 10 6 74 mpl0 ( 𝜑𝑍 = ( { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } × { ( 0g𝑅 ) } ) )
98 fconstmpt ( { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } × { ( 0g𝑅 ) } ) = ( 𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ↦ ( 0g𝑅 ) )
99 97 98 eqtr2di ( 𝜑 → ( 𝑝 ∈ { ∈ ( ℕ0m 𝐼 ) ∣ finSupp 0 } ↦ ( 0g𝑅 ) ) = 𝑍 )
100 17 96 99 3eqtrd ( 𝜑𝐹 = 𝑍 )