Theorem oldmaded

Description: An element of an old set is an element of a made set. (Contributed by Scott Fenton, 27-Feb-2026)

	Ref	Expression
Hypothesis	oldmaded.1	|- ( ph -> A e. ( _Old ` B ) )
Assertion	oldmaded	|- ( ph -> A e. ( _Made ` B ) )

Proof

Step	Hyp	Ref	Expression
1		oldmaded.1	|- ( ph -> A e. ( _Old ` B ) )
2		oldssmade	|- ( _Old ` B ) C_ ( _Made ` B )
3	2 1	sselid	|- ( ph -> A e. ( _Made ` B ) )