Theorem somo 5635

Description: A totally ordered set has at most one minimal element. (Contributed by Mario Carneiro, 24-Jun-2015.) (Revised by NM, 16-Jun-2017.)

Assertion

Ref	Expression
somo	⊢ (𝑅 Or 𝐴 → ∃*𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥)

Distinct variable groups:   𝑥,𝑦,𝐴   𝑥,𝑅,𝑦

Proof of Theorem somo

Dummy variable 𝑧 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		breq1 5151	. . . . . . . . . . 11 ⊢ (𝑦 = 𝑥 → (𝑦𝑅𝑧 ↔ 𝑥𝑅𝑧))
2	1	notbid 318	. . . . . . . . . 10 ⊢ (𝑦 = 𝑥 → (¬ 𝑦𝑅𝑧 ↔ ¬ 𝑥𝑅𝑧))
3	2	rspcv 3618	. . . . . . . . 9 ⊢ (𝑥 ∈ 𝐴 → (∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧 → ¬ 𝑥𝑅𝑧))
4		breq1 5151	. . . . . . . . . . 11 ⊢ (𝑦 = 𝑧 → (𝑦𝑅𝑥 ↔ 𝑧𝑅𝑥))
5	4	notbid 318	. . . . . . . . . 10 ⊢ (𝑦 = 𝑧 → (¬ 𝑦𝑅𝑥 ↔ ¬ 𝑧𝑅𝑥))
6	5	rspcv 3618	. . . . . . . . 9 ⊢ (𝑧 ∈ 𝐴 → (∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 → ¬ 𝑧𝑅𝑥))
7	3, 6	im2anan9 620	. . . . . . . 8 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → ((∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥) → (¬ 𝑥𝑅𝑧 ∧ ¬ 𝑧𝑅𝑥)))
8	7	ancomsd 465	. . . . . . 7 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → ((∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧) → (¬ 𝑥𝑅𝑧 ∧ ¬ 𝑧𝑅𝑥)))
9	8	imp 406	. . . . . 6 ⊢ (((𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) ∧ (∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧)) → (¬ 𝑥𝑅𝑧 ∧ ¬ 𝑧𝑅𝑥))
10		ioran 985	. . . . . . 7 ⊢ (¬ (𝑥𝑅𝑧 ∨ 𝑧𝑅𝑥) ↔ (¬ 𝑥𝑅𝑧 ∧ ¬ 𝑧𝑅𝑥))
11		solin 5623	. . . . . . . . . 10 ⊢ ((𝑅 Or 𝐴 ∧ (𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (𝑥𝑅𝑧 ∨ 𝑥 = 𝑧 ∨ 𝑧𝑅𝑥))
12		df-3or 1087	. . . . . . . . . 10 ⊢ ((𝑥𝑅𝑧 ∨ 𝑥 = 𝑧 ∨ 𝑧𝑅𝑥) ↔ ((𝑥𝑅𝑧 ∨ 𝑥 = 𝑧) ∨ 𝑧𝑅𝑥))
13	11, 12	sylib 218	. . . . . . . . 9 ⊢ ((𝑅 Or 𝐴 ∧ (𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ((𝑥𝑅𝑧 ∨ 𝑥 = 𝑧) ∨ 𝑧𝑅𝑥))
14		or32 925	. . . . . . . . 9 ⊢ (((𝑥𝑅𝑧 ∨ 𝑥 = 𝑧) ∨ 𝑧𝑅𝑥) ↔ ((𝑥𝑅𝑧 ∨ 𝑧𝑅𝑥) ∨ 𝑥 = 𝑧))
15	13, 14	sylib 218	. . . . . . . 8 ⊢ ((𝑅 Or 𝐴 ∧ (𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ((𝑥𝑅𝑧 ∨ 𝑧𝑅𝑥) ∨ 𝑥 = 𝑧))
16	15	ord 864	. . . . . . 7 ⊢ ((𝑅 Or 𝐴 ∧ (𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (¬ (𝑥𝑅𝑧 ∨ 𝑧𝑅𝑥) → 𝑥 = 𝑧))
17	10, 16	biimtrrid 243	. . . . . 6 ⊢ ((𝑅 Or 𝐴 ∧ (𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → ((¬ 𝑥𝑅𝑧 ∧ ¬ 𝑧𝑅𝑥) → 𝑥 = 𝑧))
18	9, 17	syl5 34	. . . . 5 ⊢ ((𝑅 Or 𝐴 ∧ (𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴)) → (((𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) ∧ (∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧)) → 𝑥 = 𝑧))
19	18	exp4b 430	. . . 4 ⊢ (𝑅 Or 𝐴 → ((𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → ((𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → ((∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧) → 𝑥 = 𝑧))))
20	19	pm2.43d 53	. . 3 ⊢ (𝑅 Or 𝐴 → ((𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐴) → ((∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧) → 𝑥 = 𝑧)))
21	20	ralrimivv 3198	. 2 ⊢ (𝑅 Or 𝐴 → ∀𝑥 ∈ 𝐴 ∀𝑧 ∈ 𝐴 ((∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧) → 𝑥 = 𝑧))
22		breq2 5152	. . . . 5 ⊢ (𝑥 = 𝑧 → (𝑦𝑅𝑥 ↔ 𝑦𝑅𝑧))
23	22	notbid 318	. . . 4 ⊢ (𝑥 = 𝑧 → (¬ 𝑦𝑅𝑥 ↔ ¬ 𝑦𝑅𝑧))
24	23	ralbidv 3176	. . 3 ⊢ (𝑥 = 𝑧 → (∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ↔ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧))
25	24	rmo4 3739	. 2 ⊢ (∃*𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ↔ ∀𝑥 ∈ 𝐴 ∀𝑧 ∈ 𝐴 ((∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥 ∧ ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑧) → 𝑥 = 𝑧))
26	21, 25	sylibr 234	1 ⊢ (𝑅 Or 𝐴 → ∃*𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ¬ 𝑦𝑅𝑥)

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 395   ∨ wo 847   ∨ w3o 1085   ∈ wcel 2106  ∀wral 3059  ∃*wrmo 3377   class class class wbr 5148   Or wor 5596

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1908  ax-6 1965  ax-7 2005  ax-8 2108  ax-9 2116  ax-ext 2706

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3or 1087  df-3an 1088  df-tru 1540  df-fal 1550  df-ex 1777  df-sb 2063  df-mo 2538  df-clab 2713  df-cleq 2727  df-clel 2814  df-ral 3060  df-rmo 3378  df-rab 3434  df-v 3480  df-dif 3966  df-un 3968  df-ss 3980  df-nul 4340  df-if 4532  df-sn 4632  df-pr 4634  df-op 4638  df-br 5149  df-so 5598

This theorem is referenced by:  wereu  5685  wereu2  5686  nomaxmo  27758  nominmo  27759