[complex] Clarify the range of return values of log

Author: tkoeppe

source/numerics.tex

@@ -1119,7 +1119,7 @@
 \begin{itemdescr}
 \pnum
 \returns
-The complex base e exponential of \tcode{x}.
+The complex base-$e$ exponential of \tcode{x}.
 \end{itemdescr}
 
 \indexlibrary{\idxcode{log}!\idxcode{complex}}%
@@ -1134,14 +1134,9 @@
 
 \pnum
 \returns
-The complex natural (base e) logarithm of \tcode{x},
-in the range of a strip mathematically unbounded along the
-real axis and in the interval \crange{-i times pi}{i times pi}
-along the imaginary axis.
-When \tcode{x} is a negative real
-number,
-\tcode{imag(log(x))}
-is pi.
+The complex natural (base-$e$) logarithm of \tcode{x}. For all \tcode{x},
+\tcode{imag(log(x))} lies in the interval \crange{$-\pi$}{$\pi$}, and
+when \tcode{x} is a negative real number, \tcode{imag(log(x))} is $\pi$.
 \end{itemdescr}
 
 \indexlibrary{\idxcode{log10}!\idxcode{complex}}%
@@ -1156,8 +1151,8 @@
 
 \pnum
 \returns
-The complex common (base 10) logarithm of \tcode{x}, defined as
-\tcode{log(x)/log(10)}.
+The complex common (base-$10$) logarithm of \tcode{x}, defined as
+\tcode{log(x) / log(10)}.
 \end{itemdescr}
 
 \indexlibrary{\idxcode{pow}!\idxcode{complex}}%