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	⊢ ( 𝜑 → 𝐴 ⊆ ℝ )
Assertion	ssrexr	⊢ ( 𝜑 → 𝐴 ⊆ ℝ* )

Proof

Step	Hyp	Ref	Expression
1		ssrexr.1	⊢ ( 𝜑 → 𝐴 ⊆ ℝ )
2		ressxr	⊢ ℝ ⊆ ℝ*
3	1 2	sstrdi	⊢ ( 𝜑 → 𝐴 ⊆ ℝ* )