Metamath Proof Explorer


Theorem ttcsnmin

Description: The singleton transitive closure is the minimal transitive class containing A as an element. (Contributed by Matthew House, 6-Apr-2026)

Ref Expression
Assertion ttcsnmin
|- ( ( A e. B /\ Tr B ) -> TC+ { A } C_ B )

Proof

Step Hyp Ref Expression
1 snssi
 |-  ( A e. B -> { A } C_ B )
2 ttcmin
 |-  ( ( { A } C_ B /\ Tr B ) -> TC+ { A } C_ B )
3 1 2 sylan
 |-  ( ( A e. B /\ Tr B ) -> TC+ { A } C_ B )