Metamath Proof Explorer


Theorem lindfind

Description: A linearly independent family is independent: no nonzero element multiple can be expressed as a linear combination of the others. (Contributed by Stefan O'Rear, 24-Feb-2015)

Ref Expression
Hypotheses lindfind.s · = ( ·𝑠𝑊 )
lindfind.n 𝑁 = ( LSpan ‘ 𝑊 )
lindfind.l 𝐿 = ( Scalar ‘ 𝑊 )
lindfind.z 0 = ( 0g𝐿 )
lindfind.k 𝐾 = ( Base ‘ 𝐿 )
Assertion lindfind ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → ¬ ( 𝐴 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) )

Proof

Step Hyp Ref Expression
1 lindfind.s · = ( ·𝑠𝑊 )
2 lindfind.n 𝑁 = ( LSpan ‘ 𝑊 )
3 lindfind.l 𝐿 = ( Scalar ‘ 𝑊 )
4 lindfind.z 0 = ( 0g𝐿 )
5 lindfind.k 𝐾 = ( Base ‘ 𝐿 )
6 simplr ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → 𝐸 ∈ dom 𝐹 )
7 eldifsn ( 𝐴 ∈ ( 𝐾 ∖ { 0 } ) ↔ ( 𝐴𝐾𝐴0 ) )
8 7 biimpri ( ( 𝐴𝐾𝐴0 ) → 𝐴 ∈ ( 𝐾 ∖ { 0 } ) )
9 8 adantl ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → 𝐴 ∈ ( 𝐾 ∖ { 0 } ) )
10 simpll ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → 𝐹 LIndF 𝑊 )
11 3 5 elbasfv ( 𝐴𝐾𝑊 ∈ V )
12 11 ad2antrl ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → 𝑊 ∈ V )
13 rellindf Rel LIndF
14 13 brrelex1i ( 𝐹 LIndF 𝑊𝐹 ∈ V )
15 14 ad2antrr ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → 𝐹 ∈ V )
16 eqid ( Base ‘ 𝑊 ) = ( Base ‘ 𝑊 )
17 16 1 2 3 5 4 islindf ( ( 𝑊 ∈ V ∧ 𝐹 ∈ V ) → ( 𝐹 LIndF 𝑊 ↔ ( 𝐹 : dom 𝐹 ⟶ ( Base ‘ 𝑊 ) ∧ ∀ 𝑒 ∈ dom 𝐹𝑎 ∈ ( 𝐾 ∖ { 0 } ) ¬ ( 𝑎 · ( 𝐹𝑒 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) ) ) )
18 12 15 17 syl2anc ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → ( 𝐹 LIndF 𝑊 ↔ ( 𝐹 : dom 𝐹 ⟶ ( Base ‘ 𝑊 ) ∧ ∀ 𝑒 ∈ dom 𝐹𝑎 ∈ ( 𝐾 ∖ { 0 } ) ¬ ( 𝑎 · ( 𝐹𝑒 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) ) ) )
19 10 18 mpbid ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → ( 𝐹 : dom 𝐹 ⟶ ( Base ‘ 𝑊 ) ∧ ∀ 𝑒 ∈ dom 𝐹𝑎 ∈ ( 𝐾 ∖ { 0 } ) ¬ ( 𝑎 · ( 𝐹𝑒 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) ) )
20 19 simprd ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → ∀ 𝑒 ∈ dom 𝐹𝑎 ∈ ( 𝐾 ∖ { 0 } ) ¬ ( 𝑎 · ( 𝐹𝑒 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) )
21 fveq2 ( 𝑒 = 𝐸 → ( 𝐹𝑒 ) = ( 𝐹𝐸 ) )
22 21 oveq2d ( 𝑒 = 𝐸 → ( 𝑎 · ( 𝐹𝑒 ) ) = ( 𝑎 · ( 𝐹𝐸 ) ) )
23 sneq ( 𝑒 = 𝐸 → { 𝑒 } = { 𝐸 } )
24 23 difeq2d ( 𝑒 = 𝐸 → ( dom 𝐹 ∖ { 𝑒 } ) = ( dom 𝐹 ∖ { 𝐸 } ) )
25 24 imaeq2d ( 𝑒 = 𝐸 → ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) = ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) )
26 25 fveq2d ( 𝑒 = 𝐸 → ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) = ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) )
27 22 26 eleq12d ( 𝑒 = 𝐸 → ( ( 𝑎 · ( 𝐹𝑒 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) ↔ ( 𝑎 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) ) )
28 27 notbid ( 𝑒 = 𝐸 → ( ¬ ( 𝑎 · ( 𝐹𝑒 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) ↔ ¬ ( 𝑎 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) ) )
29 oveq1 ( 𝑎 = 𝐴 → ( 𝑎 · ( 𝐹𝐸 ) ) = ( 𝐴 · ( 𝐹𝐸 ) ) )
30 29 eleq1d ( 𝑎 = 𝐴 → ( ( 𝑎 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) ↔ ( 𝐴 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) ) )
31 30 notbid ( 𝑎 = 𝐴 → ( ¬ ( 𝑎 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) ↔ ¬ ( 𝐴 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) ) )
32 28 31 rspc2va ( ( ( 𝐸 ∈ dom 𝐹𝐴 ∈ ( 𝐾 ∖ { 0 } ) ) ∧ ∀ 𝑒 ∈ dom 𝐹𝑎 ∈ ( 𝐾 ∖ { 0 } ) ¬ ( 𝑎 · ( 𝐹𝑒 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝑒 } ) ) ) ) → ¬ ( 𝐴 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) )
33 6 9 20 32 syl21anc ( ( ( 𝐹 LIndF 𝑊𝐸 ∈ dom 𝐹 ) ∧ ( 𝐴𝐾𝐴0 ) ) → ¬ ( 𝐴 · ( 𝐹𝐸 ) ) ∈ ( 𝑁 ‘ ( 𝐹 “ ( dom 𝐹 ∖ { 𝐸 } ) ) ) )