Definition df-s3 12725

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

Assertion

Ref	Expression
df-s3	|- <" A B C "> = ( <" A B "> ++ <" 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 12718	. 2 class <" A B C ">
5	1, 2	cs2 12717	. . 3 class <" A B ">
6	3	cs1 12441	. . 3 class <" C ">
7		cconcat 12440	. . 3 class ++
8	5, 6, 7	co 6196	. 2 class ( <" A B "> ++ <" C "> )
9	4, 8	wceq 1399	1 wff <" A B C "> = ( <" A B "> ++ <" C "> )

This definition is referenced by:  s3eqd  12739  s3cld  12746  s3cli  12755  s3fv0  12764  s3fv1  12765  s3fv2  12766  s3len  12767  s4prop  12774  s3co  12780  s1s2  12782  s1s3  12783  s2s2  12788  s4s3  12790  repsw3  12800  konigsberg  25108