Metamath Proof Explorer


Theorem topnfbey

Description: Nothing seems to be impossible to Prof. Lirpa. After years of intensive research, he managed to find a proof that when given a chance to reach infinity, one could indeed go beyond, thus giving formal soundness to Buzz Lightyear's motto "To infinity... and beyond!" (Contributed by Prof. Loof Lirpa, 1-Apr-2020) (Revised by Thierry Arnoux, 2-Aug-2020) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion topnfbey ( 𝐵 ∈ ( 0 ... +∞ ) → +∞ < 𝐵 )

Proof

Step Hyp Ref Expression
1 noel ⊢ ¬ 𝐵 ∈ ∅
2 pnfxr ⊢ +∞ ∈ ℝ*
3 xrltnr ⊢ ( +∞ ∈ ℝ* → ¬ +∞ < +∞ )
4 2 3 ax-mp ⊢ ¬ +∞ < +∞
5 zre ⊢ ( +∞ ∈ ℤ → +∞ ∈ ℝ )
6 ltpnf ⊢ ( +∞ ∈ ℝ → +∞ < +∞ )
7 5 6 syl ⊢ ( +∞ ∈ ℤ → +∞ < +∞ )
8 4 7 mto ⊢ ¬ +∞ ∈ ℤ
9 8 intnan ⊢ ¬ ( 0 ∈ ℤ ∧ +∞ ∈ ℤ )
10 fzf ⊢ ... : ( ℤ × ℤ ) ⟶ 𝒫 ℤ
11 10 fdmi ⊢ dom ... = ( ℤ × ℤ )
12 11 ndmov ⊢ ( ¬ ( 0 ∈ ℤ ∧ +∞ ∈ ℤ ) → ( 0 ... +∞ ) = ∅ )
13 9 12 ax-mp ⊢ ( 0 ... +∞ ) = ∅
14 13 eleq2i ⊢ ( 𝐵 ∈ ( 0 ... +∞ ) ↔ 𝐵 ∈ ∅ )
15 1 14 mtbir ⊢ ¬ 𝐵 ∈ ( 0 ... +∞ )
16 15 pm2.21i ⊢ ( 𝐵 ∈ ( 0 ... +∞ ) → +∞ < 𝐵 )