Theorem smoel 8290

Description: If 𝑥 is less than 𝑦 then a strictly monotone function's value will be strictly less at 𝑥 than at 𝑦. (Contributed by Andrew Salmon, 22-Nov-2011.)

Assertion

Ref	Expression
smoel	⊢ ((Smo 𝐵 ∧ 𝐴 ∈ dom 𝐵 ∧ 𝐶 ∈ 𝐴) → (𝐵‘𝐶) ∈ (𝐵‘𝐴))

Proof of Theorem smoel

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		smodm 8281	. . . . 5 ⊢ (Smo 𝐵 → Ord dom 𝐵)
2		ordtr1 6354	. . . . . . 7 ⊢ (Ord dom 𝐵 → ((𝐶 ∈ 𝐴 ∧ 𝐴 ∈ dom 𝐵) → 𝐶 ∈ dom 𝐵))
3	2	ancomsd 466	. . . . . 6 ⊢ (Ord dom 𝐵 → ((𝐴 ∈ dom 𝐵 ∧ 𝐶 ∈ 𝐴) → 𝐶 ∈ dom 𝐵))
4	3	expdimp 453	. . . . 5 ⊢ ((Ord dom 𝐵 ∧ 𝐴 ∈ dom 𝐵) → (𝐶 ∈ 𝐴 → 𝐶 ∈ dom 𝐵))
5	1, 4	sylan 586	. . . 4 ⊢ ((Smo 𝐵 ∧ 𝐴 ∈ dom 𝐵) → (𝐶 ∈ 𝐴 → 𝐶 ∈ dom 𝐵))
6		df-smo 8276	. . . . . 6 ⊢ (Smo 𝐵 ↔ (𝐵:dom 𝐵⟶On ∧ Ord dom 𝐵 ∧ ∀𝑥 ∈ dom 𝐵∀𝑦 ∈ dom 𝐵(𝑥 ∈ 𝑦 → (𝐵‘𝑥) ∈ (𝐵‘𝑦))))
7		eleq1 2827	. . . . . . . . . . 11 ⊢ (𝑥 = 𝐶 → (𝑥 ∈ 𝑦 ↔ 𝐶 ∈ 𝑦))
8		fveq2 6827	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝐶 → (𝐵‘𝑥) = (𝐵‘𝐶))
9	8	eleq1d 2824	. . . . . . . . . . 11 ⊢ (𝑥 = 𝐶 → ((𝐵‘𝑥) ∈ (𝐵‘𝑦) ↔ (𝐵‘𝐶) ∈ (𝐵‘𝑦)))
10	7, 9	imbi12d 345	. . . . . . . . . 10 ⊢ (𝑥 = 𝐶 → ((𝑥 ∈ 𝑦 → (𝐵‘𝑥) ∈ (𝐵‘𝑦)) ↔ (𝐶 ∈ 𝑦 → (𝐵‘𝐶) ∈ (𝐵‘𝑦))))
11		eleq2 2828	. . . . . . . . . . 11 ⊢ (𝑦 = 𝐴 → (𝐶 ∈ 𝑦 ↔ 𝐶 ∈ 𝐴))
12		fveq2 6827	. . . . . . . . . . . 12 ⊢ (𝑦 = 𝐴 → (𝐵‘𝑦) = (𝐵‘𝐴))
13	12	eleq2d 2825	. . . . . . . . . . 11 ⊢ (𝑦 = 𝐴 → ((𝐵‘𝐶) ∈ (𝐵‘𝑦) ↔ (𝐵‘𝐶) ∈ (𝐵‘𝐴)))
14	11, 13	imbi12d 345	. . . . . . . . . 10 ⊢ (𝑦 = 𝐴 → ((𝐶 ∈ 𝑦 → (𝐵‘𝐶) ∈ (𝐵‘𝑦)) ↔ (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
15	10, 14	rspc2v 3571	. . . . . . . . 9 ⊢ ((𝐶 ∈ dom 𝐵 ∧ 𝐴 ∈ dom 𝐵) → (∀𝑥 ∈ dom 𝐵∀𝑦 ∈ dom 𝐵(𝑥 ∈ 𝑦 → (𝐵‘𝑥) ∈ (𝐵‘𝑦)) → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
16	15	ancoms 459	. . . . . . . 8 ⊢ ((𝐴 ∈ dom 𝐵 ∧ 𝐶 ∈ dom 𝐵) → (∀𝑥 ∈ dom 𝐵∀𝑦 ∈ dom 𝐵(𝑥 ∈ 𝑦 → (𝐵‘𝑥) ∈ (𝐵‘𝑦)) → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
17	16	com12 32	. . . . . . 7 ⊢ (∀𝑥 ∈ dom 𝐵∀𝑦 ∈ dom 𝐵(𝑥 ∈ 𝑦 → (𝐵‘𝑥) ∈ (𝐵‘𝑦)) → ((𝐴 ∈ dom 𝐵 ∧ 𝐶 ∈ dom 𝐵) → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
18	17	3ad2ant3 1141	. . . . . 6 ⊢ ((𝐵:dom 𝐵⟶On ∧ Ord dom 𝐵 ∧ ∀𝑥 ∈ dom 𝐵∀𝑦 ∈ dom 𝐵(𝑥 ∈ 𝑦 → (𝐵‘𝑥) ∈ (𝐵‘𝑦))) → ((𝐴 ∈ dom 𝐵 ∧ 𝐶 ∈ dom 𝐵) → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
19	6, 18	sylbi 218	. . . . 5 ⊢ (Smo 𝐵 → ((𝐴 ∈ dom 𝐵 ∧ 𝐶 ∈ dom 𝐵) → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
20	19	expdimp 453	. . . 4 ⊢ ((Smo 𝐵 ∧ 𝐴 ∈ dom 𝐵) → (𝐶 ∈ dom 𝐵 → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
21	5, 20	syld 47	. . 3 ⊢ ((Smo 𝐵 ∧ 𝐴 ∈ dom 𝐵) → (𝐶 ∈ 𝐴 → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴))))
22	21	pm2.43d 53	. 2 ⊢ ((Smo 𝐵 ∧ 𝐴 ∈ dom 𝐵) → (𝐶 ∈ 𝐴 → (𝐵‘𝐶) ∈ (𝐵‘𝐴)))
23	22	3impia 1123	1 ⊢ ((Smo 𝐵 ∧ 𝐴 ∈ dom 𝐵 ∧ 𝐶 ∈ 𝐴) → (𝐵‘𝐶) ∈ (𝐵‘𝐴))

Syntax hints:   → wi 4   ∧ wa 396   ∧ w3a 1092   = wceq 1547   ∈ wcel 2119  ∀wral 3053  dom cdm 5618  Ord word 6309  Oncon0 6310  ⟶wf 6481  ‘cfv 6485  Smo wsmo 8275

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-8 2121  ax-9 2129  ax-ext 2711

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-3an 1094  df-tru 1550  df-fal 1560  df-ex 1787  df-sb 2074  df-clab 2718  df-cleq 2731  df-clel 2814  df-ral 3054  df-rab 3392  df-v 3433  df-dif 3886  df-un 3888  df-ss 3900  df-nul 4262  df-if 4455  df-sn 4556  df-pr 4558  df-op 4562  df-uni 4839  df-br 5073  df-tr 5180  df-ord 6313  df-iota 6441  df-fv 6493  df-smo 8276

This theorem is referenced by:  smoiun  8291  smoel2  8293