More doc tagging (#1357)

mathics/builtin/numbers/algebra.py

@@ -1847,7 +1847,7 @@ class PowerExpand(Builtin):
 
     <dl>
       <dt>'PowerExpand'[$expr$]
-      <dd>expands out powers of the form '(x^y)^z' and '(x*y)^z' in $expr$.
+      <dd>expands out powers of the form $(x^y)^z$ and $(x y)^z$ in $expr$.
     </dl>
 
     >> PowerExpand[(a ^ b) ^ c]

mathics/doc/documentation/1-Manual.mdoc

@@ -588,21 +588,21 @@ In fact, <em>functions</em> in \Mathics are just one aspect of <em>patterns</em>
   <dd>matches one expression.
   <dt>'Pattern'[$x$, $p$]
   <dd>matches the pattern $p$ and stores the matching sub-expression into $x$.
-  <dt>$x$'_' or 'Pattern[$x$, Blank[]]'
+  <dt>$x$'_' or 'Pattern['$x$, 'Blank[]]'
   <dd>matches one expression and stores it in $x$.
   <dt>'__' or 'BlankSequence[]'
   <dd>matches a sequence of one or more expressions.
   <dt>'___' or 'BlankNullSequence[]'
   <dd>matches a sequence of zero or more expressions.
   <dt>'_'$h$ or 'Blank'[$h$]
   <dd>matches one expression with head $h$.
-  <dt>'$x$_$h$' or 'Pattern[$x$, Blank'[$h$]]
+  <dt>$x$'_'$h$ or 'Pattern['$x$, 'Blank['$h$']]'
   <dd>matches one expression with head $h$ and stores it in $x$.
-  <dt>'$p$ | $q$' or 'Alternatives'[$p$, $q$]
+  <dt>$p$ | $q$ or 'Alternatives['$p$, $q$']'
   <dd>matches either pattern $p$ or $q$.
-  <dt>'$p$ ? $t$' or 'PatternTest'[$p$, $t$]
-  <dd>matches $p$ if the test '$t$[$p$]' yields 'True'.
-  <dt>'$p$ '/;' $c$' or 'Condition'[$p$, $c$]
+  <dt>$p$ '?' $t$ or 'PatternTest['$p$, $t$']'
+  <dd>matches $p$ if the test $t[p]$ yields 'True'.
+  <dt>$p$ '/;' $c$ or 'Condition['$p$, $c$']'
   <dd>matches $p$ if condition $c$ holds.
   <dt>'Verbatim'[$p$]
   <dd>matches an expression that equals $p$, without regarding patterns inside $p$.