Metamath Proof Explorer


Theorem pjcompi

Description: Component of a projection. (Contributed by NM, 31-Oct-1999) (Revised by Mario Carneiro, 19-May-2014) (New usage is discouraged.)

Ref Expression
Hypothesis pjidm.1 𝐻C
Assertion pjcompi ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐴 )

Proof

Step Hyp Ref Expression
1 pjidm.1 𝐻C
2 1 cheli ( 𝐴𝐻𝐴 ∈ ℋ )
3 1 choccli ( ⊥ ‘ 𝐻 ) ∈ C
4 3 cheli ( 𝐵 ∈ ( ⊥ ‘ 𝐻 ) → 𝐵 ∈ ℋ )
5 hvaddcl ( ( 𝐴 ∈ ℋ ∧ 𝐵 ∈ ℋ ) → ( 𝐴 + 𝐵 ) ∈ ℋ )
6 2 4 5 syl2an ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( 𝐴 + 𝐵 ) ∈ ℋ )
7 axpjpj ( ( 𝐻C ∧ ( 𝐴 + 𝐵 ) ∈ ℋ ) → ( 𝐴 + 𝐵 ) = ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ) )
8 1 6 7 sylancr ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( 𝐴 + 𝐵 ) = ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ) )
9 eqid ( 𝐴 + 𝐵 ) = ( 𝐴 + 𝐵 )
10 axpjcl ( ( 𝐻C ∧ ( 𝐴 + 𝐵 ) ∈ ℋ ) → ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) ∈ 𝐻 )
11 1 6 10 sylancr ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) ∈ 𝐻 )
12 axpjcl ( ( ( ⊥ ‘ 𝐻 ) ∈ C ∧ ( 𝐴 + 𝐵 ) ∈ ℋ ) → ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ∈ ( ⊥ ‘ 𝐻 ) )
13 3 6 12 sylancr ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ∈ ( ⊥ ‘ 𝐻 ) )
14 simpl ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → 𝐴𝐻 )
15 simpr ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → 𝐵 ∈ ( ⊥ ‘ 𝐻 ) )
16 1 chocunii ( ( ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) ∈ 𝐻 ∧ ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ∈ ( ⊥ ‘ 𝐻 ) ) ∧ ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) ) → ( ( ( 𝐴 + 𝐵 ) = ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ) ∧ ( 𝐴 + 𝐵 ) = ( 𝐴 + 𝐵 ) ) → ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐴 ∧ ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐵 ) ) )
17 11 13 14 15 16 syl22anc ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( ( 𝐴 + 𝐵 ) = ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ) ∧ ( 𝐴 + 𝐵 ) = ( 𝐴 + 𝐵 ) ) → ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐴 ∧ ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐵 ) ) )
18 9 17 mpan2i ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( 𝐴 + 𝐵 ) = ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) + ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) ) → ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐴 ∧ ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐵 ) ) )
19 8 18 mpd ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐴 ∧ ( ( proj ‘ ( ⊥ ‘ 𝐻 ) ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐵 ) )
20 19 simpld ( ( 𝐴𝐻𝐵 ∈ ( ⊥ ‘ 𝐻 ) ) → ( ( proj𝐻 ) ‘ ( 𝐴 + 𝐵 ) ) = 𝐴 )