Metamath Proof Explorer


Theorem ec0

Description: The empty-coset of a class is the empty set. (Contributed by Peter Mazsa, 19-May-2019)

Ref Expression
Assertion ec0 [ 𝐴 ] ∅ = ∅

Proof

Step Hyp Ref Expression
1 df-ec [ 𝐴 ] ∅ = ( ∅ “ { 𝐴 } )
2 0ima ( ∅ “ { 𝐴 } ) = ∅
3 1 2 eqtri [ 𝐴 ] ∅ = ∅