Metamath Proof Explorer


Theorem subiwrd

Description: Lemma for sseqp1 . (Contributed by Thierry Arnoux, 25-Apr-2019)

Ref Expression
Hypotheses iwrdsplit.s ⊢ φ → S ∈ V
iwrdsplit.f ⊢ φ → F : ℕ 0 ⟶ S
iwrdsplit.n ⊢ φ → N ∈ ℕ 0
Assertion subiwrd ⊢ φ → F ↾ 0 ..^ N ∈ Word S

Proof

Step Hyp Ref Expression
1 iwrdsplit.s ⊢ φ → S ∈ V
2 iwrdsplit.f ⊢ φ → F : ℕ 0 ⟶ S
3 iwrdsplit.n ⊢ φ → N ∈ ℕ 0
4 fzo0ssnn0 ⊢ 0 ..^ N ⊆ ℕ 0
5 fssres ⊢ F : ℕ 0 ⟶ S ∧ 0 ..^ N ⊆ ℕ 0 → F ↾ 0 ..^ N : 0 ..^ N ⟶ S
6 2 4 5 sylancl ⊢ φ → F ↾ 0 ..^ N : 0 ..^ N ⟶ S
7 iswrdi ⊢ F ↾ 0 ..^ N : 0 ..^ N ⟶ S → F ↾ 0 ..^ N ∈ Word S
8 6 7 syl ⊢ φ → F ↾ 0 ..^ N ∈ Word S