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 +∞ *
3 xrltnr +∞ * ¬ +∞ < +∞
4 2 3 ax-mp ¬ +∞ < +∞
5 zre +∞ +∞
6 ltpnf +∞ +∞ < +∞
7 5 6 syl +∞ +∞ < +∞
8 4 7 mto ¬ +∞
9 8 intnan ¬ 0 +∞
10 fzf : × 𝒫
11 10 fdmi dom = ×
12 11 ndmov ¬ 0 +∞ 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