Metamath Proof Explorer

Theorem bj-sngltagi

Description: The singletonization is included in the tagging. (Contributed by BJ, 6-Oct-2018)

Ref Expression
Assertion bj-sngltagi 
|- ( A e. sngl B -> A e. tag B )

Proof

Step Hyp Ref Expression
1 bj-snglsstag 
 |-  sngl B C_ tag B
2 1 sseli 
 |-  ( A e. sngl B -> A e. tag B )