Terrible-tethrathoth-by-godgahlah is equal to E100(#^^#)^^#*#^#100 using Extended Cascading-E Notation.[1] The term was coined by Sbiis Saibian.

Approximations in other notations

Notation Approximation
BEAF \(\{100,100 (X \uparrow\uparrow 2X) (1) 2\}\) [2]
Bird's array notation \(\{100,100[1 \backslash 3]1[2]2\}\)
Fast-growing hierarchy \(f_{\omega^{\varphi(1,1)+\omega} }(100)\)
\(=f_{\varepsilon_1 \omega^{\omega}}(100)\)
Hardy hierarchy \(H_{\varepsilon_1^{\omega^{\omega}}}(101)\)
Slow-growing hierarchy \(g_{\vartheta(\varepsilon_{\Omega3}\Omega^{\omega})}(99)\)


  1. Saibian, Sbiis. 4.3.7 Extended Cascading-E Numbers Part IOne to Infinity. Retrieved 2017-02-18.
  2. Using particular notation \(\{a,b (X \uparrow\uparrow X)(X \uparrow\uparrow X)\cdots(X \uparrow\uparrow X) c \#\}\) for \(\{X \uparrow\uparrow b\ \&\ a (X \uparrow\uparrow X) X \uparrow\uparrow b\ \&\ a (X \uparrow\uparrow X)\cdots X \uparrow\uparrow b\ \&\ a (X \uparrow\uparrow X) c-1 \#\}\)

See also

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