Theorem wlkdlem4 28033

Description: Lemma 4 for wlkd 28034. (Contributed by Alexander van der Vekens, 1-Feb-2018.) (Revised by AV, 23-Jan-2021.)

Hypotheses

Ref	Expression
wlkd.p	⊢ (𝜑 → 𝑃 ∈ Word V)
wlkd.f	⊢ (𝜑 → 𝐹 ∈ Word V)
wlkd.l	⊢ (𝜑 → (♯‘𝑃) = ((♯‘𝐹) + 1))
wlkd.e	⊢ (𝜑 → ∀𝑘 ∈ (0..^(♯‘𝐹)){(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘)))
wlkd.n	⊢ (𝜑 → ∀𝑘 ∈ (0..^(♯‘𝐹))(𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1)))

Assertion

Ref	Expression
wlkdlem4	⊢ (𝜑 → ∀𝑘 ∈ (0..^(♯‘𝐹))if-((𝑃‘𝑘) = (𝑃‘(𝑘 + 1)), (𝐼‘(𝐹‘𝑘)) = {(𝑃‘𝑘)}, {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))))

Distinct variable groups:   𝑘,𝐹   𝑃,𝑘   𝑘,𝐼   𝜑,𝑘

Proof of Theorem wlkdlem4

Step	Hyp	Ref	Expression
1		wlkd.e	. 2 ⊢ (𝜑 → ∀𝑘 ∈ (0..^(♯‘𝐹)){(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘)))
2		wlkd.n	. 2 ⊢ (𝜑 → ∀𝑘 ∈ (0..^(♯‘𝐹))(𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1)))
3		r19.26 3096	. . 3 ⊢ (∀𝑘 ∈ (0..^(♯‘𝐹))({(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘)) ∧ (𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1))) ↔ (∀𝑘 ∈ (0..^(♯‘𝐹)){(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘)) ∧ ∀𝑘 ∈ (0..^(♯‘𝐹))(𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1))))
4		df-ne 2945	. . . . . 6 ⊢ ((𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1)) ↔ ¬ (𝑃‘𝑘) = (𝑃‘(𝑘 + 1)))
5		ifpfal 1073	. . . . . 6 ⊢ (¬ (𝑃‘𝑘) = (𝑃‘(𝑘 + 1)) → (if-((𝑃‘𝑘) = (𝑃‘(𝑘 + 1)), (𝐼‘(𝐹‘𝑘)) = {(𝑃‘𝑘)}, {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))) ↔ {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))))
6	4, 5	sylbi 216	. . . . 5 ⊢ ((𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1)) → (if-((𝑃‘𝑘) = (𝑃‘(𝑘 + 1)), (𝐼‘(𝐹‘𝑘)) = {(𝑃‘𝑘)}, {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))) ↔ {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))))
7	6	biimparc 479	. . . 4 ⊢ (({(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘)) ∧ (𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1))) → if-((𝑃‘𝑘) = (𝑃‘(𝑘 + 1)), (𝐼‘(𝐹‘𝑘)) = {(𝑃‘𝑘)}, {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))))
8	7	ralimi 3088	. . 3 ⊢ (∀𝑘 ∈ (0..^(♯‘𝐹))({(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘)) ∧ (𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1))) → ∀𝑘 ∈ (0..^(♯‘𝐹))if-((𝑃‘𝑘) = (𝑃‘(𝑘 + 1)), (𝐼‘(𝐹‘𝑘)) = {(𝑃‘𝑘)}, {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))))
9	3, 8	sylbir 234	. 2 ⊢ ((∀𝑘 ∈ (0..^(♯‘𝐹)){(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘)) ∧ ∀𝑘 ∈ (0..^(♯‘𝐹))(𝑃‘𝑘) ≠ (𝑃‘(𝑘 + 1))) → ∀𝑘 ∈ (0..^(♯‘𝐹))if-((𝑃‘𝑘) = (𝑃‘(𝑘 + 1)), (𝐼‘(𝐹‘𝑘)) = {(𝑃‘𝑘)}, {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))))
10	1, 2, 9	syl2anc 583	1 ⊢ (𝜑 → ∀𝑘 ∈ (0..^(♯‘𝐹))if-((𝑃‘𝑘) = (𝑃‘(𝑘 + 1)), (𝐼‘(𝐹‘𝑘)) = {(𝑃‘𝑘)}, {(𝑃‘𝑘), (𝑃‘(𝑘 + 1))} ⊆ (𝐼‘(𝐹‘𝑘))))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205   ∧ wa 395  if-wif 1059   = wceq 1541   ∈ wcel 2109   ≠ wne 2944  ∀wral 3065  Vcvv 3430   ⊆ wss 3891  {csn 4566  {cpr 4568  ‘cfv 6430  (class class class)co 7268  0cc0 10855  1c1 10856   + caddc 10858  ..^cfzo 13364  ♯chash 14025  Word cword 14198

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1801  ax-4 1815

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 844  df-ifp 1060  df-ne 2945  df-ral 3070

This theorem is referenced by:  wlkd  28034