Metamath Proof Explorer


Theorem axtco2g

Description: Weak form of the Axiom of Transitive Containment using class variables and abbreviations. See ax-tco for more information. (Contributed by Matthew House, 6-Apr-2026)

Ref Expression
Assertion axtco2g
|- ( A e. V -> E. x ( A C_ x /\ Tr x ) )

Proof

Step Hyp Ref Expression
1 axtco1g
 |-  ( A e. V -> E. x ( A e. x /\ Tr x ) )
2 trss
 |-  ( Tr x -> ( A e. x -> A C_ x ) )
3 2 imdistanri
 |-  ( ( A e. x /\ Tr x ) -> ( A C_ x /\ Tr x ) )
4 3 eximi
 |-  ( E. x ( A e. x /\ Tr x ) -> E. x ( A C_ x /\ Tr x ) )
5 1 4 syl
 |-  ( A e. V -> E. x ( A C_ x /\ Tr x ) )