Metamath Proof Explorer


Theorem asclfval

Description: Function value of the algebraic scalars function. (Contributed by Mario Carneiro, 8-Mar-2015)

Ref Expression
Hypotheses asclfval.a 𝐴 = ( algSc ‘ 𝑊 )
asclfval.f 𝐹 = ( Scalar ‘ 𝑊 )
asclfval.k 𝐾 = ( Base ‘ 𝐹 )
asclfval.s · = ( ·𝑠𝑊 )
asclfval.o 1 = ( 1r𝑊 )
Assertion asclfval 𝐴 = ( 𝑥𝐾 ↦ ( 𝑥 · 1 ) )

Proof

Step Hyp Ref Expression
1 asclfval.a 𝐴 = ( algSc ‘ 𝑊 )
2 asclfval.f 𝐹 = ( Scalar ‘ 𝑊 )
3 asclfval.k 𝐾 = ( Base ‘ 𝐹 )
4 asclfval.s · = ( ·𝑠𝑊 )
5 asclfval.o 1 = ( 1r𝑊 )
6 fveq2 ( 𝑤 = 𝑊 → ( Scalar ‘ 𝑤 ) = ( Scalar ‘ 𝑊 ) )
7 6 2 eqtr4di ( 𝑤 = 𝑊 → ( Scalar ‘ 𝑤 ) = 𝐹 )
8 7 fveq2d ( 𝑤 = 𝑊 → ( Base ‘ ( Scalar ‘ 𝑤 ) ) = ( Base ‘ 𝐹 ) )
9 8 3 eqtr4di ( 𝑤 = 𝑊 → ( Base ‘ ( Scalar ‘ 𝑤 ) ) = 𝐾 )
10 fveq2 ( 𝑤 = 𝑊 → ( ·𝑠𝑤 ) = ( ·𝑠𝑊 ) )
11 10 4 eqtr4di ( 𝑤 = 𝑊 → ( ·𝑠𝑤 ) = · )
12 eqidd ( 𝑤 = 𝑊𝑥 = 𝑥 )
13 fveq2 ( 𝑤 = 𝑊 → ( 1r𝑤 ) = ( 1r𝑊 ) )
14 13 5 eqtr4di ( 𝑤 = 𝑊 → ( 1r𝑤 ) = 1 )
15 11 12 14 oveq123d ( 𝑤 = 𝑊 → ( 𝑥 ( ·𝑠𝑤 ) ( 1r𝑤 ) ) = ( 𝑥 · 1 ) )
16 9 15 mpteq12dv ( 𝑤 = 𝑊 → ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝑤 ) ) ↦ ( 𝑥 ( ·𝑠𝑤 ) ( 1r𝑤 ) ) ) = ( 𝑥𝐾 ↦ ( 𝑥 · 1 ) ) )
17 df-ascl algSc = ( 𝑤 ∈ V ↦ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝑤 ) ) ↦ ( 𝑥 ( ·𝑠𝑤 ) ( 1r𝑤 ) ) ) )
18 16 17 3 mptfvmpt ( 𝑊 ∈ V → ( algSc ‘ 𝑊 ) = ( 𝑥𝐾 ↦ ( 𝑥 · 1 ) ) )
19 fvprc ( ¬ 𝑊 ∈ V → ( algSc ‘ 𝑊 ) = ∅ )
20 mpt0 ( 𝑥 ∈ ∅ ↦ ( 𝑥 · 1 ) ) = ∅
21 19 20 eqtr4di ( ¬ 𝑊 ∈ V → ( algSc ‘ 𝑊 ) = ( 𝑥 ∈ ∅ ↦ ( 𝑥 · 1 ) ) )
22 fvprc ( ¬ 𝑊 ∈ V → ( Scalar ‘ 𝑊 ) = ∅ )
23 2 22 syl5eq ( ¬ 𝑊 ∈ V → 𝐹 = ∅ )
24 23 fveq2d ( ¬ 𝑊 ∈ V → ( Base ‘ 𝐹 ) = ( Base ‘ ∅ ) )
25 base0 ∅ = ( Base ‘ ∅ )
26 24 25 eqtr4di ( ¬ 𝑊 ∈ V → ( Base ‘ 𝐹 ) = ∅ )
27 3 26 syl5eq ( ¬ 𝑊 ∈ V → 𝐾 = ∅ )
28 27 mpteq1d ( ¬ 𝑊 ∈ V → ( 𝑥𝐾 ↦ ( 𝑥 · 1 ) ) = ( 𝑥 ∈ ∅ ↦ ( 𝑥 · 1 ) ) )
29 21 28 eqtr4d ( ¬ 𝑊 ∈ V → ( algSc ‘ 𝑊 ) = ( 𝑥𝐾 ↦ ( 𝑥 · 1 ) ) )
30 18 29 pm2.61i ( algSc ‘ 𝑊 ) = ( 𝑥𝐾 ↦ ( 𝑥 · 1 ) )
31 1 30 eqtri 𝐴 = ( 𝑥𝐾 ↦ ( 𝑥 · 1 ) )