Definition df-bj-rrbar 36105

Description: Definition of the set of extended real numbers. This aims to replace df-xr 11251. (Contributed by BJ, 29-Jun-2019.)

Assertion

Ref	Expression
df-bj-rrbar	⊢ ℝ̅ = (ℝ ∪ {-∞, +∞})

Detailed syntax breakdown of Definition df-bj-rrbar

Step	Hyp	Ref	Expression
1		crrbar 36104	. 2 class ℝ̅
2		cr 11108	. . 3 class ℝ
3		cminfty 36099	. . . 4 class -∞
4		cpinfty 36095	. . . 4 class +∞
5	3, 4	cpr 4630	. . 3 class {-∞, +∞}
6	2, 5	cun 3946	. 2 class (ℝ ∪ {-∞, +∞})
7	1, 6	wceq 1541	1 wff ℝ̅ = (ℝ ∪ {-∞, +∞})

This definition is referenced by: (None)