Definition df-frmd 17386

Description: Define a free monoid over a set i of generators, defined as the set of finite strings on I with the operation of concatenation. (Contributed by Mario Carneiro, 27-Sep-2015.)

Assertion

Ref	Expression
df-frmd	|- freeMnd = ( i e. _V |-> { <. ( Base ` ndx ) , Word i >. , <. ( +g ` ndx ) , ( ++ |` (Word i X. Word i ) ) >. } )

Detailed syntax breakdown of Definition df-frmd

Step	Hyp	Ref	Expression
1		cfrmd 17384	. 2 class freeMnd
2		vi	. . 3 setvar i
3		cvv 3200	. . 3 class _V
4		cnx 15854	. . . . . 6 class ndx
5		cbs 15857	. . . . . 6 class Base
6	4, 5	cfv 5888	. . . . 5 class ( Base ` ndx )
7	2	cv 1482	. . . . . 6 class i
8	7	cword 13291	. . . . 5 class Word i
9	6, 8	cop 4183	. . . 4 class <. ( Base ` ndx ) , Word i >.
10		cplusg 15941	. . . . . 6 class +g
11	4, 10	cfv 5888	. . . . 5 class ( +g ` ndx )
12		cconcat 13293	. . . . . 6 class ++
13	8, 8	cxp 5112	. . . . . 6 class (Word i X. Word i )
14	12, 13	cres 5116	. . . . 5 class ( ++ |` (Word i X. Word i ) )
15	11, 14	cop 4183	. . . 4 class <. ( +g ` ndx ) , ( ++ |` (Word i X. Word i ) ) >.
16	9, 15	cpr 4179	. . 3 class { <. ( Base ` ndx ) , Word i >. , <. ( +g ` ndx ) , ( ++ |` (Word i X. Word i ) ) >. }
17	2, 3, 16	cmpt 4729	. 2 class ( i e. _V |-> { <. ( Base ` ndx ) , Word i >. , <. ( +g ` ndx ) , ( ++ |` (Word i X. Word i ) ) >. } )
18	1, 17	wceq 1483	1 wff freeMnd = ( i e. _V |-> { <. ( Base ` ndx ) , Word i >. , <. ( +g ` ndx ) , ( ++ |` (Word i X. Word i ) ) >. } )

This definition is referenced by:  frmdval  17388