Definition df-pi 11818

Description: Define the constant pi, π = 3.14159..., which is the smallest positive number whose sine is zero. Definition of π in [Gleason] p. 311. (Contributed by Paul Chapman, 23-Jan-2008.) (Revised by AV, 14-Sep-2020.)

Assertion

Ref	Expression
df-pi	⊢ π = inf((ℝ+ ∩ (◡sin “ {0})), ℝ, < )

Detailed syntax breakdown of Definition df-pi

Step	Hyp	Ref	Expression
1		cpi 11812	. 2 class π
2		crp 9728	. . . 4 class ℝ+
3		csin 11809	. . . . . 6 class sin
4	3	ccnv 4662	. . . . 5 class ◡sin
5		cc0 7879	. . . . . 6 class 0
6	5	csn 3622	. . . . 5 class {0}
7	4, 6	cima 4666	. . . 4 class (◡sin “ {0})
8	2, 7	cin 3156	. . 3 class (ℝ+ ∩ (◡sin “ {0}))
9		cr 7878	. . 3 class ℝ
10		clt 8061	. . 3 class <
11	8, 9, 10	cinf 7049	. 2 class inf((ℝ+ ∩ (◡sin “ {0})), ℝ, < )
12	1, 11	wceq 1364	1 wff π = inf((ℝ+ ∩ (◡sin “ {0})), ℝ, < )

This definition is referenced by:  pilem3  15019