Theorem iocssxr

Description: An open-below, closed-above interval is a subset of the extended reals. (Contributed by FL, 29-May-2014) (Revised by Mario Carneiro, 4-Jul-2014)

	Ref	Expression
Assertion	iocssxr	|- ( A (,] B ) C_ RR*

Proof

Step	Hyp	Ref	Expression
1		df-ioc	|- (,] = ( x e. RR* , y e. RR* |-> { z e. RR* | ( x < z /\ z <_ y ) } )
2	1	ixxssxr	|- ( A (,] B ) C_ RR*