Metamath Proof Explorer


Theorem tgldimor

Description: Excluded-middle like statement allowing to treat dimension zero as a special case. (Contributed by Thierry Arnoux, 11-Apr-2019)

Ref Expression
Hypotheses tgldimor.p P = E F
tgldimor.a φ A P
Assertion tgldimor φ P = 1 2 P

Proof

Step Hyp Ref Expression
1 tgldimor.p P = E F
2 tgldimor.a φ A P
3 1 fvexi P V
4 hashv01gt1 P V P = 0 P = 1 1 < P
5 3 4 ax-mp P = 0 P = 1 1 < P
6 3orass P = 0 P = 1 1 < P P = 0 P = 1 1 < P
7 5 6 mpbi P = 0 P = 1 1 < P
8 1p1e2 1 + 1 = 2
9 1z 1
10 nn0z P 0 P
11 zltp1le 1 P 1 < P 1 + 1 P
12 9 10 11 sylancr P 0 1 < P 1 + 1 P
13 12 biimpac 1 < P P 0 1 + 1 P
14 8 13 eqbrtrrid 1 < P P 0 2 P
15 2re 2
16 15 rexri 2 *
17 pnfge 2 * 2 +∞
18 16 17 ax-mp 2 +∞
19 breq2 P = +∞ 2 P 2 +∞
20 18 19 mpbiri P = +∞ 2 P
21 20 adantl 1 < P P = +∞ 2 P
22 hashnn0pnf P V P 0 P = +∞
23 3 22 mp1i 1 < P P 0 P = +∞
24 14 21 23 mpjaodan 1 < P 2 P
25 24 orim2i P = 1 1 < P P = 1 2 P
26 25 orim2i P = 0 P = 1 1 < P P = 0 P = 1 2 P
27 7 26 mp1i φ P = 0 P = 1 2 P
28 ne0i A P P
29 hasheq0 P V P = 0 P =
30 3 29 ax-mp P = 0 P =
31 30 biimpi P = 0 P =
32 31 necon3ai P ¬ P = 0
33 2 28 32 3syl φ ¬ P = 0
34 biorf ¬ P = 0 P = 1 2 P P = 0 P = 1 2 P
35 33 34 syl φ P = 1 2 P P = 0 P = 1 2 P
36 27 35 mpbird φ P = 1 2 P