[meta.reflection.traits] Fix typos

Author: Andreas-Krug

source/meta.tex

@@ -6723,7 +6723,7 @@
 \end{codeblock}
 
 \pnum
-Ech function or function template declared above has the following behavior
+Each function or function template declared above has the following behavior
 based on the signature and return type of that function or function template.
 \begin{note}
 The associated class template need not be instantiated.
@@ -6855,7 +6855,7 @@
 \returns
 A reflection representing
 the type denoted by \tcode{tuple_element_t<$I$, T>},
-where \tcode{T} is th type represented by \tcode{dealias(type)},
+where \tcode{T} is the type represented by \tcode{dealias(type)},
 and $I$ is a constant equal to \tcode{index}.
 \end{itemdescr}
 
@@ -6882,7 +6882,7 @@
 A reflection representing the type denoted by
 \tcode{variant_alternative_t<\brk{}$I$, T>},
 where \tcode{T} is the type represented by \tcode{dealias(type)}
-and $I$ is a consant equal to \tcode{index}.
+and $I$ is a constant equal to \tcode{index}.
 \end{itemdescr}
 
 \indexlibraryglobal{type_order}%