 Intuitionistic Logic Explorer < Previous   Next > Nearby theorems Mirrors  >  Home  >  ILE Home  >  Th. List  >  ltprordil GIF version

Theorem ltprordil 6918
 Description: If a positive real is less than a second positive real, its lower cut is a subset of the second's lower cut. (Contributed by Jim Kingdon, 23-Dec-2019.)
Assertion
Ref Expression
ltprordil (𝐴<P 𝐵 → (1st𝐴) ⊆ (1st𝐵))

Proof of Theorem ltprordil
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 ltrelpr 6834 . . . 4 <P ⊆ (P × P)
21brel 4439 . . 3 (𝐴<P 𝐵 → (𝐴P𝐵P))
3 ltdfpr 6835 . . . 4 ((𝐴P𝐵P) → (𝐴<P 𝐵 ↔ ∃𝑥Q (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵))))
43biimpd 142 . . 3 ((𝐴P𝐵P) → (𝐴<P 𝐵 → ∃𝑥Q (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵))))
52, 4mpcom 36 . 2 (𝐴<P 𝐵 → ∃𝑥Q (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))
6 simpll 496 . . . . . 6 (((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) ∧ 𝑦 ∈ (1st𝐴)) → 𝐴<P 𝐵)
7 simpr 108 . . . . . 6 (((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) ∧ 𝑦 ∈ (1st𝐴)) → 𝑦 ∈ (1st𝐴))
8 simprrl 506 . . . . . . 7 ((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) → 𝑥 ∈ (2nd𝐴))
98adantr 270 . . . . . 6 (((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) ∧ 𝑦 ∈ (1st𝐴)) → 𝑥 ∈ (2nd𝐴))
102simpld 110 . . . . . . . 8 (𝐴<P 𝐵𝐴P)
11 prop 6804 . . . . . . . 8 (𝐴P → ⟨(1st𝐴), (2nd𝐴)⟩ ∈ P)
1210, 11syl 14 . . . . . . 7 (𝐴<P 𝐵 → ⟨(1st𝐴), (2nd𝐴)⟩ ∈ P)
13 prltlu 6816 . . . . . . 7 ((⟨(1st𝐴), (2nd𝐴)⟩ ∈ P𝑦 ∈ (1st𝐴) ∧ 𝑥 ∈ (2nd𝐴)) → 𝑦 <Q 𝑥)
1412, 13syl3an1 1203 . . . . . 6 ((𝐴<P 𝐵𝑦 ∈ (1st𝐴) ∧ 𝑥 ∈ (2nd𝐴)) → 𝑦 <Q 𝑥)
156, 7, 9, 14syl3anc 1170 . . . . 5 (((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) ∧ 𝑦 ∈ (1st𝐴)) → 𝑦 <Q 𝑥)
16 simprrr 507 . . . . . . 7 ((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) → 𝑥 ∈ (1st𝐵))
1716adantr 270 . . . . . 6 (((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) ∧ 𝑦 ∈ (1st𝐴)) → 𝑥 ∈ (1st𝐵))
182simprd 112 . . . . . . . 8 (𝐴<P 𝐵𝐵P)
19 prop 6804 . . . . . . . 8 (𝐵P → ⟨(1st𝐵), (2nd𝐵)⟩ ∈ P)
2018, 19syl 14 . . . . . . 7 (𝐴<P 𝐵 → ⟨(1st𝐵), (2nd𝐵)⟩ ∈ P)
21 prcdnql 6813 . . . . . . 7 ((⟨(1st𝐵), (2nd𝐵)⟩ ∈ P𝑥 ∈ (1st𝐵)) → (𝑦 <Q 𝑥𝑦 ∈ (1st𝐵)))
2220, 21sylan 277 . . . . . 6 ((𝐴<P 𝐵𝑥 ∈ (1st𝐵)) → (𝑦 <Q 𝑥𝑦 ∈ (1st𝐵)))
236, 17, 22syl2anc 403 . . . . 5 (((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) ∧ 𝑦 ∈ (1st𝐴)) → (𝑦 <Q 𝑥𝑦 ∈ (1st𝐵)))
2415, 23mpd 13 . . . 4 (((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) ∧ 𝑦 ∈ (1st𝐴)) → 𝑦 ∈ (1st𝐵))
2524ex 113 . . 3 ((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) → (𝑦 ∈ (1st𝐴) → 𝑦 ∈ (1st𝐵)))
2625ssrdv 3015 . 2 ((𝐴<P 𝐵 ∧ (𝑥Q ∧ (𝑥 ∈ (2nd𝐴) ∧ 𝑥 ∈ (1st𝐵)))) → (1st𝐴) ⊆ (1st𝐵))
275, 26rexlimddv 2487 1 (𝐴<P 𝐵 → (1st𝐴) ⊆ (1st𝐵))
 Colors of variables: wff set class Syntax hints:   → wi 4   ∧ wa 102   ∈ wcel 1434  ∃wrex 2354   ⊆ wss 2983  ⟨cop 3420   class class class wbr 3806  ‘cfv 4953  1st c1st 5818  2nd c2nd 5819  Qcnq 6609
 Copyright terms: Public domain W3C validator