Metamath Proof Explorer


Theorem incssnn0

Description: Transitivity induction of subsets, lemma for nacsfix . (Contributed by Stefan O'Rear, 4-Apr-2015)

Ref Expression
Assertion incssnn0 ⊢ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 ∧ B ∈ ℤ ≥ A → F ⁡ A ⊆ F ⁡ B

Proof

Step Hyp Ref Expression
1 fveq2 ⊢ a = A → F ⁡ a = F ⁡ A
2 1 sseq2d ⊢ a = A → F ⁡ A ⊆ F ⁡ a ↔ F ⁡ A ⊆ F ⁡ A
3 2 imbi2d ⊢ a = A → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ a ↔ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ A
4 fveq2 ⊢ a = b → F ⁡ a = F ⁡ b
5 4 sseq2d ⊢ a = b → F ⁡ A ⊆ F ⁡ a ↔ F ⁡ A ⊆ F ⁡ b
6 5 imbi2d ⊢ a = b → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ a ↔ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ b
7 fveq2 ⊢ a = b + 1 → F ⁡ a = F ⁡ b + 1
8 7 sseq2d ⊢ a = b + 1 → F ⁡ A ⊆ F ⁡ a ↔ F ⁡ A ⊆ F ⁡ b + 1
9 8 imbi2d ⊢ a = b + 1 → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ a ↔ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ b + 1
10 fveq2 ⊢ a = B → F ⁡ a = F ⁡ B
11 10 sseq2d ⊢ a = B → F ⁡ A ⊆ F ⁡ a ↔ F ⁡ A ⊆ F ⁡ B
12 11 imbi2d ⊢ a = B → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ a ↔ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ B
13 ssid ⊢ F ⁡ A ⊆ F ⁡ A
14 13 2a1i ⊢ A ∈ ℤ → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ A
15 eluznn0 ⊢ A ∈ ℕ 0 ∧ b ∈ ℤ ≥ A → b ∈ ℕ 0
16 15 ancoms ⊢ b ∈ ℤ ≥ A ∧ A ∈ ℕ 0 → b ∈ ℕ 0
17 fveq2 ⊢ x = b → F ⁡ x = F ⁡ b
18 fvoveq1 ⊢ x = b → F ⁡ x + 1 = F ⁡ b + 1
19 17 18 sseq12d ⊢ x = b → F ⁡ x ⊆ F ⁡ x + 1 ↔ F ⁡ b ⊆ F ⁡ b + 1
20 19 rspcv ⊢ b ∈ ℕ 0 → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → F ⁡ b ⊆ F ⁡ b + 1
21 16 20 syl ⊢ b ∈ ℤ ≥ A ∧ A ∈ ℕ 0 → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → F ⁡ b ⊆ F ⁡ b + 1
22 21 expimpd ⊢ b ∈ ℤ ≥ A → A ∈ ℕ 0 ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → F ⁡ b ⊆ F ⁡ b + 1
23 22 ancomsd ⊢ b ∈ ℤ ≥ A → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ b ⊆ F ⁡ b + 1
24 sstr2 ⊢ F ⁡ A ⊆ F ⁡ b → F ⁡ b ⊆ F ⁡ b + 1 → F ⁡ A ⊆ F ⁡ b + 1
25 24 com12 ⊢ F ⁡ b ⊆ F ⁡ b + 1 → F ⁡ A ⊆ F ⁡ b → F ⁡ A ⊆ F ⁡ b + 1
26 23 25 syl6 ⊢ b ∈ ℤ ≥ A → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ b → F ⁡ A ⊆ F ⁡ b + 1
27 26 a2d ⊢ b ∈ ℤ ≥ A → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ b → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ b + 1
28 3 6 9 12 14 27 uzind4 ⊢ B ∈ ℤ ≥ A → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → F ⁡ A ⊆ F ⁡ B
29 28 com12 ⊢ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 → B ∈ ℤ ≥ A → F ⁡ A ⊆ F ⁡ B
30 29 3impia ⊢ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ A ∈ ℕ 0 ∧ B ∈ ℤ ≥ A → F ⁡ A ⊆ F ⁡ B