Theorem ssrexr

Description: A subset of the reals is a subset of the extended reals. (Contributed by Glauco Siliprandi, 2-Jan-2022)

	Ref	Expression
Hypothesis	ssrexr.1	|- ( ph -> A C_ RR )
Assertion	ssrexr	|- ( ph -> A C_ RR* )

Proof

Step	Hyp	Ref	Expression
1		ssrexr.1	|- ( ph -> A C_ RR )
2		ressxr	|- RR C_ RR*
3	1 2	sstrdi	|- ( ph -> A C_ RR* )