Metamath Proof Explorer


Theorem pjaddii

Description: Projection of vector sum is sum of projections. (Contributed by NM, 31-Oct-1999) (New usage is discouraged.)

Ref Expression
Hypotheses pjidm.1 𝐻C
pjidm.2 𝐴 ∈ ℋ
pjadj.3 𝐵 ∈ ℋ
Assertion pjaddii ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) )

Proof

Step Hyp Ref Expression
1 pjidm.1 𝐻C
2 pjidm.2 𝐴 ∈ ℋ
3 pjadj.3 𝐵 ∈ ℋ
4 1 2 pjpji 𝐴 = ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) )
5 1 3 pjpji 𝐵 = ( ( ( proj𝐻 ) ‘ 𝐵 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) )
6 4 5 oveq12i ( 𝐴 + 𝐵 ) = ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) ) + ( ( ( proj𝐻 ) ‘ 𝐵 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) )
7 1 2 pjhclii ( ( proj𝐻 ) ‘ 𝐴 ) ∈ ℋ
8 1 choccli ( ⊥ ‘ 𝐻 ) ∈ C
9 8 2 pjhclii ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) ∈ ℋ
10 1 3 pjhclii ( ( proj𝐻 ) ‘ 𝐵 ) ∈ ℋ
11 8 3 pjhclii ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ∈ ℋ
12 7 9 10 11 hvadd4i ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) ) + ( ( ( proj𝐻 ) ‘ 𝐵 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) ) = ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) + ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) )
13 6 12 eqtri ( 𝐴 + 𝐵 ) = ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) + ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) )
14 13 fveq2i ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = ( ( proj𝐻 ) ‘ ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) + ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) ) )
15 1 chshii 𝐻S
16 1 2 pjclii ( ( proj𝐻 ) ‘ 𝐴 ) ∈ 𝐻
17 1 3 pjclii ( ( proj𝐻 ) ‘ 𝐵 ) ∈ 𝐻
18 shaddcl ( ( 𝐻S ∧ ( ( proj𝐻 ) ‘ 𝐴 ) ∈ 𝐻 ∧ ( ( proj𝐻 ) ‘ 𝐵 ) ∈ 𝐻 ) → ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) ∈ 𝐻 )
19 15 16 17 18 mp3an ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) ∈ 𝐻
20 8 chshii ( ⊥ ‘ 𝐻 ) ∈ S
21 8 2 pjclii ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) ∈ ( ⊥ ‘ 𝐻 )
22 8 3 pjclii ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ∈ ( ⊥ ‘ 𝐻 )
23 shaddcl ( ( ( ⊥ ‘ 𝐻 ) ∈ S ∧ ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) ∈ ( ⊥ ‘ 𝐻 ) ∧ ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) ∈ ( ⊥ ‘ 𝐻 ) )
24 20 21 22 23 mp3an ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) ∈ ( ⊥ ‘ 𝐻 )
25 1 pjcompi ( ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) ∈ 𝐻 ∧ ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( proj𝐻 ) ‘ ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) + ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) ) ) = ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) )
26 19 24 25 mp2an ( ( proj𝐻 ) ‘ ( ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) ) + ( ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐴 ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ 𝐵 ) ) ) ) = ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) )
27 14 26 eqtri ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = ( ( ( proj𝐻 ) ‘ 𝐴 ) + ( ( proj𝐻 ) ‘ 𝐵 ) )