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 ) → ( 𝑃𝐾 ) = 0 )

Proof

Step Hyp Ref Expression
1 axlowdimlem7.1 𝑃 = ( { ⟨ 3 , - 1 ⟩ } ∪ ( ( ( 1 ... 𝑁 ) ∖ { 3 } ) × { 0 } ) )
2 1 fveq1i ( 𝑃𝐾 ) = ( ( { ⟨ 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 syl5eq ( ( 𝐾 ∈ ( 1 ... 𝑁 ) ∧ 𝐾 ≠ 3 ) → ( 𝑃𝐾 ) = 0 )