Metamath Proof Explorer


Theorem prjspnerlem

Description: A lemma showing that the equivalence relation used in prjspnval2 and the equivalence relation used in prjspval are equal, but only with the antecedent K e. DivRing . (Contributed by SN, 15-Jul-2023)

Ref Expression
Hypotheses prjspnerlem.e = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙𝑆 𝑥 = ( 𝑙 · 𝑦 ) ) }
prjspnerlem.w 𝑊 = ( 𝐾 freeLMod ( 0 ... 𝑁 ) )
prjspnerlem.b 𝐵 = ( ( Base ‘ 𝑊 ) ∖ { ( 0g𝑊 ) } )
prjspnerlem.s 𝑆 = ( Base ‘ 𝐾 )
prjspnerlem.x · = ( ·𝑠𝑊 )
Assertion prjspnerlem ( 𝐾 ∈ DivRing → = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙 ∈ ( Base ‘ ( Scalar ‘ 𝑊 ) ) 𝑥 = ( 𝑙 · 𝑦 ) ) } )

Proof

Step Hyp Ref Expression
1 prjspnerlem.e = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙𝑆 𝑥 = ( 𝑙 · 𝑦 ) ) }
2 prjspnerlem.w 𝑊 = ( 𝐾 freeLMod ( 0 ... 𝑁 ) )
3 prjspnerlem.b 𝐵 = ( ( Base ‘ 𝑊 ) ∖ { ( 0g𝑊 ) } )
4 prjspnerlem.s 𝑆 = ( Base ‘ 𝐾 )
5 prjspnerlem.x · = ( ·𝑠𝑊 )
6 ovex ( 0 ... 𝑁 ) ∈ V
7 2 frlmsca ( ( 𝐾 ∈ DivRing ∧ ( 0 ... 𝑁 ) ∈ V ) → 𝐾 = ( Scalar ‘ 𝑊 ) )
8 6 7 mpan2 ( 𝐾 ∈ DivRing → 𝐾 = ( Scalar ‘ 𝑊 ) )
9 8 fveq2d ( 𝐾 ∈ DivRing → ( Base ‘ 𝐾 ) = ( Base ‘ ( Scalar ‘ 𝑊 ) ) )
10 4 9 syl5eq ( 𝐾 ∈ DivRing → 𝑆 = ( Base ‘ ( Scalar ‘ 𝑊 ) ) )
11 10 rexeqdv ( 𝐾 ∈ DivRing → ( ∃ 𝑙𝑆 𝑥 = ( 𝑙 · 𝑦 ) ↔ ∃ 𝑙 ∈ ( Base ‘ ( Scalar ‘ 𝑊 ) ) 𝑥 = ( 𝑙 · 𝑦 ) ) )
12 11 anbi2d ( 𝐾 ∈ DivRing → ( ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙𝑆 𝑥 = ( 𝑙 · 𝑦 ) ) ↔ ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙 ∈ ( Base ‘ ( Scalar ‘ 𝑊 ) ) 𝑥 = ( 𝑙 · 𝑦 ) ) ) )
13 12 opabbidv ( 𝐾 ∈ DivRing → { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙𝑆 𝑥 = ( 𝑙 · 𝑦 ) ) } = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙 ∈ ( Base ‘ ( Scalar ‘ 𝑊 ) ) 𝑥 = ( 𝑙 · 𝑦 ) ) } )
14 1 13 syl5eq ( 𝐾 ∈ DivRing → = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐵𝑦𝐵 ) ∧ ∃ 𝑙 ∈ ( Base ‘ ( Scalar ‘ 𝑊 ) ) 𝑥 = ( 𝑙 · 𝑦 ) ) } )