Metamath Proof Explorer


Theorem axlowdimlem9

Description: Lemma for axlowdim . Calculate the value of P away from three. (Contributed by Scott Fenton, 21-Apr-2013)

Ref Expression
Hypothesis axlowdimlem7.1 ⊢ 𝑃 = ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) )
Assertion axlowdimlem9 ( ( 𝐾 ∈ ( 1 ... 𝑁 ) ∧ 𝐾 ≠ 3 ) → ( 𝑃 ‘ 𝐾 ) = 0 )

Proof

Step Hyp Ref Expression
1 axlowdimlem7.1 ⊢ 𝑃 = ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) )
2 1 fveq1i ⊢ ( 𝑃 ‘ 𝐾 ) = ( ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ) ‘ 𝐾 )
3 eldifsn ⊢ ( 𝐾 ∈ ( ( 1 ... 𝑁 ) ∖ { 3 } ) ↔ ( 𝐾 ∈ ( 1 ... 𝑁 ) ∧ 𝐾 ≠ 3 ) )
4 disjdif ⊢ ( { 3 } ∩ ( ( 1 ... 𝑁 ) ∖ { 3 } ) ) = ∅
5 3ex ⊢ 3 ∈ V
6 negex ⊢ - 1 ∈ V
7 5 6 fnsn ⊢ { ⟨ 3 , - 1 ⟩ } Fn { 3 }
8 c0ex ⊢ 0 ∈ V
9 8 fconst ⊢ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) : ( ( 1 ... 𝑁 ) ∖ { 3 } ) ⟶ { 0 }
10 ffn ⊢ ( ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) : ( ( 1 ... 𝑁 ) ∖ { 3 } ) ⟶ { 0 } → ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) Fn ( ( 1 ... 𝑁 ) ∖ { 3 } ) )
11 9 10 ax-mp ⊢ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) Fn ( ( 1 ... 𝑁 ) ∖ { 3 } )
12 fvun2 ⊢ ( ( { ⟨ 3 , - 1 ⟩ } Fn { 3 } ∧ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) Fn ( ( 1 ... 𝑁 ) ∖ { 3 } ) ∧ ( ( { 3 } ∩ ( ( 1 ... 𝑁 ) ∖ { 3 } ) ) = ∅ ∧ 𝐾 ∈ ( ( 1 ... 𝑁 ) ∖ { 3 } ) ) ) → ( ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ) ‘ 𝐾 ) = ( ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ‘ 𝐾 ) )
13 7 11 12 mp3an12 ⊢ ( ( ( { 3 } ∩ ( ( 1 ... 𝑁 ) ∖ { 3 } ) ) = ∅ ∧ 𝐾 ∈ ( ( 1 ... 𝑁 ) ∖ { 3 } ) ) → ( ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ) ‘ 𝐾 ) = ( ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ‘ 𝐾 ) )
14 4 13 mpan ⊢ ( 𝐾 ∈ ( ( 1 ... 𝑁 ) ∖ { 3 } ) → ( ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ) ‘ 𝐾 ) = ( ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ‘ 𝐾 ) )
15 8 fvconst2 ⊢ ( 𝐾 ∈ ( ( 1 ... 𝑁 ) ∖ { 3 } ) → ( ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ‘ 𝐾 ) = 0 )
16 14 15 eqtrd ⊢ ( 𝐾 ∈ ( ( 1 ... 𝑁 ) ∖ { 3 } ) → ( ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ) ‘ 𝐾 ) = 0 )
17 3 16 sylbir ⊢ ( ( 𝐾 ∈ ( 1 ... 𝑁 ) ∧ 𝐾 ≠ 3 ) → ( ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) ) ‘ 𝐾 ) = 0 )
18 2 17 eqtrid ⊢ ( ( 𝐾 ∈ ( 1 ... 𝑁 ) ∧ 𝐾 ≠ 3 ) → ( 𝑃 ‘ 𝐾 ) = 0 )