Metamath Proof Explorer


Theorem psslinpr

Description: Proper subset is a linear ordering on positive reals. Part of Proposition 9-3.3 of Gleason p. 122. (Contributed by NM, 25-Feb-1996) (New usage is discouraged.)

Ref Expression
Assertion psslinpr ( ( 𝐴P𝐵P ) → ( 𝐴𝐵𝐴 = 𝐵𝐵𝐴 ) )

Proof

Step Hyp Ref Expression
1 elprnq ( ( 𝐴P𝑥𝐴 ) → 𝑥Q )
2 prub ( ( ( 𝐵P𝑦𝐵 ) ∧ 𝑥Q ) → ( ¬ 𝑥𝐵𝑦 <Q 𝑥 ) )
3 1 2 sylan2 ( ( ( 𝐵P𝑦𝐵 ) ∧ ( 𝐴P𝑥𝐴 ) ) → ( ¬ 𝑥𝐵𝑦 <Q 𝑥 ) )
4 prcdnq ( ( 𝐴P𝑥𝐴 ) → ( 𝑦 <Q 𝑥𝑦𝐴 ) )
5 4 adantl ( ( ( 𝐵P𝑦𝐵 ) ∧ ( 𝐴P𝑥𝐴 ) ) → ( 𝑦 <Q 𝑥𝑦𝐴 ) )
6 3 5 syld ( ( ( 𝐵P𝑦𝐵 ) ∧ ( 𝐴P𝑥𝐴 ) ) → ( ¬ 𝑥𝐵𝑦𝐴 ) )
7 6 exp43 ( 𝐵P → ( 𝑦𝐵 → ( 𝐴P → ( 𝑥𝐴 → ( ¬ 𝑥𝐵𝑦𝐴 ) ) ) ) )
8 7 com3r ( 𝐴P → ( 𝐵P → ( 𝑦𝐵 → ( 𝑥𝐴 → ( ¬ 𝑥𝐵𝑦𝐴 ) ) ) ) )
9 8 imp ( ( 𝐴P𝐵P ) → ( 𝑦𝐵 → ( 𝑥𝐴 → ( ¬ 𝑥𝐵𝑦𝐴 ) ) ) )
10 9 imp4a ( ( 𝐴P𝐵P ) → ( 𝑦𝐵 → ( ( 𝑥𝐴 ∧ ¬ 𝑥𝐵 ) → 𝑦𝐴 ) ) )
11 10 com23 ( ( 𝐴P𝐵P ) → ( ( 𝑥𝐴 ∧ ¬ 𝑥𝐵 ) → ( 𝑦𝐵𝑦𝐴 ) ) )
12 11 alrimdv ( ( 𝐴P𝐵P ) → ( ( 𝑥𝐴 ∧ ¬ 𝑥𝐵 ) → ∀ 𝑦 ( 𝑦𝐵𝑦𝐴 ) ) )
13 12 exlimdv ( ( 𝐴P𝐵P ) → ( ∃ 𝑥 ( 𝑥𝐴 ∧ ¬ 𝑥𝐵 ) → ∀ 𝑦 ( 𝑦𝐵𝑦𝐴 ) ) )
14 nss ( ¬ 𝐴𝐵 ↔ ∃ 𝑥 ( 𝑥𝐴 ∧ ¬ 𝑥𝐵 ) )
15 sspss ( 𝐴𝐵 ↔ ( 𝐴𝐵𝐴 = 𝐵 ) )
16 14 15 xchnxbi ( ¬ ( 𝐴𝐵𝐴 = 𝐵 ) ↔ ∃ 𝑥 ( 𝑥𝐴 ∧ ¬ 𝑥𝐵 ) )
17 sspss ( 𝐵𝐴 ↔ ( 𝐵𝐴𝐵 = 𝐴 ) )
18 dfss2 ( 𝐵𝐴 ↔ ∀ 𝑦 ( 𝑦𝐵𝑦𝐴 ) )
19 17 18 bitr3i ( ( 𝐵𝐴𝐵 = 𝐴 ) ↔ ∀ 𝑦 ( 𝑦𝐵𝑦𝐴 ) )
20 13 16 19 3imtr4g ( ( 𝐴P𝐵P ) → ( ¬ ( 𝐴𝐵𝐴 = 𝐵 ) → ( 𝐵𝐴𝐵 = 𝐴 ) ) )
21 20 orrd ( ( 𝐴P𝐵P ) → ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ ( 𝐵𝐴𝐵 = 𝐴 ) ) )
22 df-3or ( ( 𝐴𝐵𝐴 = 𝐵𝐵𝐴 ) ↔ ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ 𝐵𝐴 ) )
23 or32 ( ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ 𝐵𝐴 ) ↔ ( ( 𝐴𝐵𝐵𝐴 ) ∨ 𝐴 = 𝐵 ) )
24 orordir ( ( ( 𝐴𝐵𝐵𝐴 ) ∨ 𝐴 = 𝐵 ) ↔ ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ ( 𝐵𝐴𝐴 = 𝐵 ) ) )
25 eqcom ( 𝐵 = 𝐴𝐴 = 𝐵 )
26 25 orbi2i ( ( 𝐵𝐴𝐵 = 𝐴 ) ↔ ( 𝐵𝐴𝐴 = 𝐵 ) )
27 26 orbi2i ( ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ ( 𝐵𝐴𝐵 = 𝐴 ) ) ↔ ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ ( 𝐵𝐴𝐴 = 𝐵 ) ) )
28 24 27 bitr4i ( ( ( 𝐴𝐵𝐵𝐴 ) ∨ 𝐴 = 𝐵 ) ↔ ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ ( 𝐵𝐴𝐵 = 𝐴 ) ) )
29 22 23 28 3bitri ( ( 𝐴𝐵𝐴 = 𝐵𝐵𝐴 ) ↔ ( ( 𝐴𝐵𝐴 = 𝐵 ) ∨ ( 𝐵𝐴𝐵 = 𝐴 ) ) )
30 21 29 sylibr ( ( 𝐴P𝐵P ) → ( 𝐴𝐵𝐴 = 𝐵𝐵𝐴 ) )