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	$$⊢\phi \to A\subseteq ℝ$$
Assertion	ssrexr	$$⊢\phi \to A\subseteq {ℝ}^{*}$$

Proof

Step	Hyp	Ref	Expression
1		ssrexr.1	$$⊢\phi \to A\subseteq ℝ$$
2		ressxr	$$⊢ℝ\subseteq {ℝ}^{*}$$
3	1 2	sstrdi	$$⊢\phi \to A\subseteq {ℝ}^{*}$$