1.NounThe arithmetic operator consisting of repeated exponentiation, by analogy with exponentiation being repeated multiplication and multiplication being repeated addition,
b
a
{\displaystyle ^{b}a}
denoting
a
{\displaystyle a}
to the power of
a
{\displaystyle a}
to the power of
…
{\displaystyle \ldots }
to the power of
a
{\displaystyle a}
, in which
a
{\displaystyle a}
appears
b
{\displaystyle b}
times.