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 var FMnd = i V j i ⟨“ j ”⟩

Detailed syntax breakdown

Step Hyp Ref Expression
0 cvrmd class var FMnd
1 vi setvar i
2 cvv class V
3 vj setvar j
4 1 cv setvar i
5 3 cv setvar j
6 5 cs1 class ⟨“ j ”⟩
7 3 4 6 cmpt class j i ⟨“ j ”⟩
8 1 2 7 cmpt class i V j i ⟨“ j ”⟩
9 0 8 wceq wff var FMnd = i V j i ⟨“ j ”⟩