Quadrix

The quadrix is equal to 9,999. The term was coined by André Joyce.http://michaelhalm.tripod.com/mathematics_beyond_the_googol.html
As it is the largest four-digit number in decimal, it has been used in carnahan.c, chan-3.c and pete-6.c.http://djm.cc/bignum-results.txt
== Etymology ==
The 2 parts of the name, “quadr” and “ix”, mean 4 and 9, respectively.
== Approximations ==
Notation 	Lower bound 	Upper bound
Scientific notation 	\(9.999\times10^3\) 	\(9.999\times10^3\)
Arrow notation 	\(99\uparrow2\) 	\(10\uparrow4\)
Steinhaus-Moser Notation 	5[3] 	6[3]
Copy notation 	9[4] 	9[4]
Chained arrow notation 	\(99\rightarrow2\) 	\(10\rightarrow4\)
Taro's multivariable Ackermann function	A(3,10) 	A(3,11)
Pound-Star Notation 	#*(70)*2 	#*(71)*2
PlantStar's Debut Notation 	[2] 	[3]
BEAF 	{99,2} 	{10,4}
Hyper-E notation 	99E2 	E4
Bashicu matrix system 	(0)[99] 	(0)[100]
Hyperfactorial array notation 	7! 	8!
Bird's array notation 	{99,2} 	{10,4}
Strong array notation 	s(99,2) 	s(10,4)
Fast-growing hierarchy 	\(f_1(f_2(9))\) 	\(f_2(10)\)
Hardy hierarchy 	\(H_{\omega^2+\omega}(9)\)	\(H_{\omega^2}(10)\)
Slow-growing hierarchy 	\(g_{\omega^2}(99)\) 	\(g_{\omega^4}(10)\)
== Sources ==
Category:Numbers
Category:Bignum Bakeoff
Category:Class 1
Category:Numbers by André Joyce
Category:Numbers with 4 to 6 digits
Category:Odd numbers
Category:Repdigit numbers