Metamath Proof Explorer


Theorem pjf2

Description: A projection is a function from the base set to the subspace. (Contributed by Mario Carneiro, 16-Oct-2015)

Ref Expression
Hypotheses pjf.k ⊢ K = proj ⁡ W
pjf.v ⊢ V = Base W
Assertion pjf2 ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → K ⁡ T : V ⟶ T

Proof

Step Hyp Ref Expression
1 pjf.k ⊢ K = proj ⁡ W
2 pjf.v ⊢ V = Base W
3 eqid ⊢ + W = + W
4 eqid ⊢ LSSum ⁡ W = LSSum ⁡ W
5 eqid ⊢ 0 W = 0 W
6 eqid ⊢ Cntz ⁡ W = Cntz ⁡ W
7 phllmod ⊢ W ∈ PreHil → W ∈ LMod
8 7 adantr ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → W ∈ LMod
9 eqid ⊢ LSubSp ⁡ W = LSubSp ⁡ W
10 9 lsssssubg ⊢ W ∈ LMod → LSubSp ⁡ W ⊆ SubGrp ⁡ W
11 8 10 syl ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → LSubSp ⁡ W ⊆ SubGrp ⁡ W
12 eqid ⊢ ocv ⁡ W = ocv ⁡ W
13 2 9 12 4 1 pjdm2 ⊢ W ∈ PreHil → T ∈ dom ⁡ K ↔ T ∈ LSubSp ⁡ W ∧ T LSSum ⁡ W ocv ⁡ W ⁡ T = V
14 13 simprbda ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T ∈ LSubSp ⁡ W
15 11 14 sseldd ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T ∈ SubGrp ⁡ W
16 2 9 lssss ⊢ T ∈ LSubSp ⁡ W → T ⊆ V
17 14 16 syl ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T ⊆ V
18 2 12 9 ocvlss ⊢ W ∈ PreHil ∧ T ⊆ V → ocv ⁡ W ⁡ T ∈ LSubSp ⁡ W
19 17 18 syldan ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → ocv ⁡ W ⁡ T ∈ LSubSp ⁡ W
20 11 19 sseldd ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → ocv ⁡ W ⁡ T ∈ SubGrp ⁡ W
21 12 9 5 ocvin ⊢ W ∈ PreHil ∧ T ∈ LSubSp ⁡ W → T ∩ ocv ⁡ W ⁡ T = 0 W
22 14 21 syldan ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T ∩ ocv ⁡ W ⁡ T = 0 W
23 lmodabl ⊢ W ∈ LMod → W ∈ Abel
24 8 23 syl ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → W ∈ Abel
25 6 24 15 20 ablcntzd ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T ⊆ Cntz ⁡ W ⁡ ocv ⁡ W ⁡ T
26 eqid ⊢ proj 1 ⁡ W = proj 1 ⁡ W
27 3 4 5 6 15 20 22 25 26 pj1f ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T proj 1 ⁡ W ocv ⁡ W ⁡ T : T LSSum ⁡ W ocv ⁡ W ⁡ T ⟶ T
28 12 26 1 pjval ⊢ T ∈ dom ⁡ K → K ⁡ T = T proj 1 ⁡ W ocv ⁡ W ⁡ T
29 28 adantl ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → K ⁡ T = T proj 1 ⁡ W ocv ⁡ W ⁡ T
30 29 eqcomd ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T proj 1 ⁡ W ocv ⁡ W ⁡ T = K ⁡ T
31 13 simplbda ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T LSSum ⁡ W ocv ⁡ W ⁡ T = V
32 30 31 feq12d ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → T proj 1 ⁡ W ocv ⁡ W ⁡ T : T LSSum ⁡ W ocv ⁡ W ⁡ T ⟶ T ↔ K ⁡ T : V ⟶ T
33 27 32 mpbid ⊢ W ∈ PreHil ∧ T ∈ dom ⁡ K → K ⁡ T : V ⟶ T