This must be a silly question, but while reading the book of Borel and Ji on compactifications of symmetric and locally symmetric spaces I got completely stuck on the notation. Does the notation $x^y$ make sense for two elements $x, y$ in a Lie group?
Here is the setup, let $P$ be a parabolic subgroup of a Lie group $G$, $P = MAN$ its Langlands decomposition. Could someone help me decipher what is the author means by $n^a$ for two elements $a\in A$ and $n\in N$. This happens on page 35 and several other places throughout the book.