Metamath Proof Explorer


Theorem subiwrd

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

Ref Expression
Hypotheses iwrdsplit.s ( 𝜑𝑆 ∈ V )
iwrdsplit.f ( 𝜑𝐹 : ℕ0𝑆 )
iwrdsplit.n ( 𝜑𝑁 ∈ ℕ0 )
Assertion subiwrd ( 𝜑 → ( 𝐹 ↾ ( 0 ..^ 𝑁 ) ) ∈ Word 𝑆 )

Proof

Step Hyp Ref Expression
1 iwrdsplit.s ( 𝜑𝑆 ∈ V )
2 iwrdsplit.f ( 𝜑𝐹 : ℕ0𝑆 )
3 iwrdsplit.n ( 𝜑𝑁 ∈ ℕ0 )
4 fzo0ssnn0 ( 0 ..^ 𝑁 ) ⊆ ℕ0
5 fssres ( ( 𝐹 : ℕ0𝑆 ∧ ( 0 ..^ 𝑁 ) ⊆ ℕ0 ) → ( 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 )