Definition df-s3 11305

Description: Define the length 3 word constructor. (Contributed by Mario Carneiro, 26-Feb-2016.)

Assertion

Ref	Expression
df-s3	⊢ ⟨“𝐴𝐵𝐶”⟩ = (⟨“𝐴𝐵”⟩ ++ ⟨“𝐶”⟩)

Detailed syntax breakdown of Definition df-s3

Step	Hyp	Ref	Expression
1		cA	. . 3 class 𝐴
2		cB	. . 3 class 𝐵
3		cC	. . 3 class 𝐶
4	1, 2, 3	cs3 11298	. 2 class ⟨“𝐴𝐵𝐶”⟩
5	1, 2	cs2 11297	. . 3 class ⟨“𝐴𝐵”⟩
6	3	cs1 11163	. . 3 class ⟨“𝐶”⟩
7		cconcat 11138	. . 3 class ++
8	5, 6, 7	co 6007	. 2 class (⟨“𝐴𝐵”⟩ ++ ⟨“𝐶”⟩)
9	4, 8	wceq 1395	1 wff ⟨“𝐴𝐵𝐶”⟩ = (⟨“𝐴𝐵”⟩ ++ ⟨“𝐶”⟩)

This definition is referenced by:  s3eqd  11319  s3cld  11327  s3fv0g  11339  s3fv1g  11340