Theorem s6cld

Description: A length 6 string is a word. (Contributed by Mario Carneiro, 27-Feb-2016)

	Ref	Expression
Hypotheses	s2cld.1	⊢ ( 𝜑 → 𝐴 ∈ 𝑋 )
	s2cld.2	⊢ ( 𝜑 → 𝐵 ∈ 𝑋 )
	s3cld.3	⊢ ( 𝜑 → 𝐶 ∈ 𝑋 )
	s4cld.4	⊢ ( 𝜑 → 𝐷 ∈ 𝑋 )
	s5cld.5	⊢ ( 𝜑 → 𝐸 ∈ 𝑋 )
	s6cld.6	⊢ ( 𝜑 → 𝐹 ∈ 𝑋 )
Assertion	s6cld	⊢ ( 𝜑 → ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 ”⟩ ∈ Word 𝑋 )

Proof

Step	Hyp	Ref	Expression
1		s2cld.1	⊢ ( 𝜑 → 𝐴 ∈ 𝑋 )
2		s2cld.2	⊢ ( 𝜑 → 𝐵 ∈ 𝑋 )
3		s3cld.3	⊢ ( 𝜑 → 𝐶 ∈ 𝑋 )
4		s4cld.4	⊢ ( 𝜑 → 𝐷 ∈ 𝑋 )
5		s5cld.5	⊢ ( 𝜑 → 𝐸 ∈ 𝑋 )
6		s6cld.6	⊢ ( 𝜑 → 𝐹 ∈ 𝑋 )
7		df-s6	⊢ ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 ”⟩ = ( ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 ”⟩ ++ ⟨“ 𝐹 ”⟩ )
8	1 2 3 4 5	s5cld	⊢ ( 𝜑 → ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 ”⟩ ∈ Word 𝑋 )
9	7 8 6	cats1cld	⊢ ( 𝜑 → ⟨“ 𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 ”⟩ ∈ Word 𝑋 )