Definition df-r 10881

Description: Define the set of real numbers. (Contributed by NM, 22-Feb-1996.) (New usage is discouraged.)

Assertion

Ref	Expression
df-r	⊢ ℝ = (R × {0R})

Detailed syntax breakdown of Definition df-r

Step	Hyp	Ref	Expression
1		cr 10870	. 2 class ℝ
2		cnr 10621	. . 3 class R
3		c0r 10622	. . . 4 class 0R
4	3	csn 4561	. . 3 class {0R}
5	2, 4	cxp 5587	. 2 class (R × {0R})
6	1, 5	wceq 1539	1 wff ℝ = (R × {0R})

This definition is referenced by:  opelreal  10886  elreal  10887  elreal2  10888  axresscn  10904  ax1rid  10917  avril1  28827