Metamath Proof Explorer


Theorem lnon0

Description: The domain of a nonzero linear operator contains a nonzero vector. (Contributed by NM, 15-Dec-2007) (New usage is discouraged.)

Ref Expression
Hypotheses lnon0.1 ⊢ X = BaseSet ⁡ U
lnon0.6 ⊢ Z = 0 vec ⁡ U
lnon0.0 ⊢ O = U 0 op W
lnon0.7 ⊢ L = U LnOp W
Assertion lnon0 ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L ∧ T ≠ O → ∃ x ∈ X x ≠ Z

Proof

Step Hyp Ref Expression
1 lnon0.1 ⊢ X = BaseSet ⁡ U
2 lnon0.6 ⊢ Z = 0 vec ⁡ U
3 lnon0.0 ⊢ O = U 0 op W
4 lnon0.7 ⊢ L = U LnOp W
5 ralnex ⊢ ∀ x ∈ X ¬ x ≠ Z ↔ ¬ ∃ x ∈ X x ≠ Z
6 nne ⊢ ¬ x ≠ Z ↔ x = Z
7 6 ralbii ⊢ ∀ x ∈ X ¬ x ≠ Z ↔ ∀ x ∈ X x = Z
8 5 7 bitr3i ⊢ ¬ ∃ x ∈ X x ≠ Z ↔ ∀ x ∈ X x = Z
9 fveq2 ⊢ x = Z → T ⁡ x = T ⁡ Z
10 eqid ⊢ BaseSet ⁡ W = BaseSet ⁡ W
11 eqid ⊢ 0 vec ⁡ W = 0 vec ⁡ W
12 1 10 2 11 4 lno0 ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → T ⁡ Z = 0 vec ⁡ W
13 9 12 sylan9eqr ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L ∧ x = Z → T ⁡ x = 0 vec ⁡ W
14 13 ex ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → x = Z → T ⁡ x = 0 vec ⁡ W
15 14 ralimdv ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → ∀ x ∈ X x = Z → ∀ x ∈ X T ⁡ x = 0 vec ⁡ W
16 1 10 4 lnof ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → T : X ⟶ BaseSet ⁡ W
17 16 ffnd ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → T Fn X
18 15 17 jctild ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → ∀ x ∈ X x = Z → T Fn X ∧ ∀ x ∈ X T ⁡ x = 0 vec ⁡ W
19 fconstfv ⊢ T : X ⟶ 0 vec ⁡ W ↔ T Fn X ∧ ∀ x ∈ X T ⁡ x = 0 vec ⁡ W
20 fvex ⊢ 0 vec ⁡ W ∈ V
21 20 fconst2 ⊢ T : X ⟶ 0 vec ⁡ W ↔ T = X × 0 vec ⁡ W
22 19 21 bitr3i ⊢ T Fn X ∧ ∀ x ∈ X T ⁡ x = 0 vec ⁡ W ↔ T = X × 0 vec ⁡ W
23 18 22 imbitrdi ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → ∀ x ∈ X x = Z → T = X × 0 vec ⁡ W
24 1 11 3 0ofval ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec → O = X × 0 vec ⁡ W
25 24 3adant3 ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → O = X × 0 vec ⁡ W
26 25 eqeq2d ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → T = O ↔ T = X × 0 vec ⁡ W
27 23 26 sylibrd ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → ∀ x ∈ X x = Z → T = O
28 8 27 biimtrid ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → ¬ ∃ x ∈ X x ≠ Z → T = O
29 28 necon1ad ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L → T ≠ O → ∃ x ∈ X x ≠ Z
30 29 imp ⊢ U ∈ NrmCVec ∧ W ∈ NrmCVec ∧ T ∈ L ∧ T ≠ O → ∃ x ∈ X x ≠ Z