Metamath Proof Explorer


Definition df-lm

Description: Define a function on topologies whose value is the convergence relation for sequences into the given topological space. Although f is typically a sequence (a function from an upperset of integers) with values in the topological space, it need not be. Note, however, that the limit property concerns only values at integers, so that the real-valued function ( x e. RR |-> ( sin( _pi x. x ) ) ) converges to zero (in the standard topology on the reals) with this definition. (Contributed by NM, 7-Sep-2006)

Ref Expression
Assertion df-lm 𝑡 = ( 𝑗 ∈ Top ↦ { ⟨ 𝑓 , 𝑥 ⟩ ∣ ( 𝑓 ∈ ( 𝑗pm ℂ ) ∧ 𝑥 𝑗 ∧ ∀ 𝑢𝑗 ( 𝑥𝑢 → ∃ 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢 ) ) } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 clm 𝑡
1 vj 𝑗
2 ctop Top
3 vf 𝑓
4 vx 𝑥
5 3 cv 𝑓
6 1 cv 𝑗
7 6 cuni 𝑗
8 cpm pm
9 cc
10 7 9 8 co ( 𝑗pm ℂ )
11 5 10 wcel 𝑓 ∈ ( 𝑗pm ℂ )
12 4 cv 𝑥
13 12 7 wcel 𝑥 𝑗
14 vu 𝑢
15 14 cv 𝑢
16 12 15 wcel 𝑥𝑢
17 vy 𝑦
18 cuz
19 18 crn ran ℤ
20 17 cv 𝑦
21 5 20 cres ( 𝑓𝑦 )
22 20 15 21 wf ( 𝑓𝑦 ) : 𝑦𝑢
23 22 17 19 wrex 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢
24 16 23 wi ( 𝑥𝑢 → ∃ 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢 )
25 24 14 6 wral 𝑢𝑗 ( 𝑥𝑢 → ∃ 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢 )
26 11 13 25 w3a ( 𝑓 ∈ ( 𝑗pm ℂ ) ∧ 𝑥 𝑗 ∧ ∀ 𝑢𝑗 ( 𝑥𝑢 → ∃ 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢 ) )
27 26 3 4 copab { ⟨ 𝑓 , 𝑥 ⟩ ∣ ( 𝑓 ∈ ( 𝑗pm ℂ ) ∧ 𝑥 𝑗 ∧ ∀ 𝑢𝑗 ( 𝑥𝑢 → ∃ 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢 ) ) }
28 1 2 27 cmpt ( 𝑗 ∈ Top ↦ { ⟨ 𝑓 , 𝑥 ⟩ ∣ ( 𝑓 ∈ ( 𝑗pm ℂ ) ∧ 𝑥 𝑗 ∧ ∀ 𝑢𝑗 ( 𝑥𝑢 → ∃ 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢 ) ) } )
29 0 28 wceq 𝑡 = ( 𝑗 ∈ Top ↦ { ⟨ 𝑓 , 𝑥 ⟩ ∣ ( 𝑓 ∈ ( 𝑗pm ℂ ) ∧ 𝑥 𝑗 ∧ ∀ 𝑢𝑗 ( 𝑥𝑢 → ∃ 𝑦 ∈ ran ℤ ( 𝑓𝑦 ) : 𝑦𝑢 ) ) } )