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 ∈ 𝑉 → ∃ 𝑥 ( 𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ) )

Proof

Step Hyp Ref Expression
1 axtco1g ⊢ ( 𝐴 ∈ 𝑉 → ∃ 𝑥 ( 𝐴 ∈ 𝑥 ∧ Tr 𝑥 ) )
2 trss ⊢ ( Tr 𝑥 → ( 𝐴 ∈ 𝑥 → 𝐴 ⊆ 𝑥 ) )
3 2 imdistanri ⊢ ( ( 𝐴 ∈ 𝑥 ∧ Tr 𝑥 ) → ( 𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ) )
4 3 eximi ⊢ ( ∃ 𝑥 ( 𝐴 ∈ 𝑥 ∧ Tr 𝑥 ) → ∃ 𝑥 ( 𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ) )
5 1 4 syl ⊢ ( 𝐴 ∈ 𝑉 → ∃ 𝑥 ( 𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ) )