Theorem s8len

Description: The length of a length 8 string. (Contributed by Mario Carneiro, 26-Feb-2016)

	Ref	Expression
Assertion	s8len	⊢ ( ♯ ‘ ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 𝐺 𝐻 ”⟩ ) = 8

Proof

Step	Hyp	Ref	Expression
1		df-s8	⊢ ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 𝐺 𝐻 ”⟩ = ( ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 𝐺 ”⟩ ++ ⟨“ 𝐻 ”⟩ )
2		s7cli	⊢ ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 𝐺 ”⟩ ∈ Word V
3		s7len	⊢ ( ♯ ‘ ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 𝐺 ”⟩ ) = 7
4		7p1e8	⊢ ( 7 + 1 ) = 8
5	1 2 3 4	cats1len	⊢ ( ♯ ‘ ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 𝐺 𝐻 ”⟩ ) = 8