[linalg.general] Use E as a placeholder for an expression

Author: jensmaurer

source/numerics.tex

@@ -11196,12 +11196,12 @@
 \pnum
 For the effects of all functions in \ref{linalg},
 when the effects are described as
-``computes $R = EXPR$'' or ``compute $R = EXPR$''
-(for some $R$ and mathematical expression $EXPR$),
+``computes $R = E$'' or ``compute $R = E$''
+(for some $R$ and mathematical expression $E$),
 the following apply:
 \begin{itemize}
 \item
-$EXPR$ has
+$E$ has
       the conventional mathematical meaning as written.
 \item
 The pattern $x^T$ should be read as