Metamath Proof Explorer


Definition df-coels

Description: Define the class of coelements on the class A , see also the alternate definition dfcoels . Possible definitions are the special cases of dfcoss3 and dfcoss4 . (Contributed by Peter Mazsa, 20-Nov-2019)

Ref Expression
Assertion df-coels A=E-1A

Detailed syntax breakdown

Step Hyp Ref Expression
0 cA classA
1 0 ccoels classA
2 cep classE
3 2 ccnv classE-1
4 3 0 cres classE-1A
5 4 ccoss classE-1A
6 1 5 wceq wffA=E-1A