Metamath Proof Explorer


Definition df-vrmd

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)

Ref Expression
Assertion df-vrmd
|- varFMnd = ( i e. _V |-> ( j e. i |-> <" j "> ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cvrmd
 |-  varFMnd
1 vi
 |-  i
2 cvv
 |-  _V
3 vj
 |-  j
4 1 cv
 |-  i
5 3 cv
 |-  j
6 5 cs1
 |-  <" j ">
7 3 4 6 cmpt
 |-  ( j e. i |-> <" j "> )
8 1 2 7 cmpt
 |-  ( i e. _V |-> ( j e. i |-> <" j "> ) )
9 0 8 wceq
 |-  varFMnd = ( i e. _V |-> ( j e. i |-> <" j "> ) )