[expr] Replace 'could' and 'might'

as directed by ISO/CS.

Author: jensmaurer

source/expressions.tex

@@ -114,7 +114,7 @@
 \begin{codeblock}
 a = (a + (b + 32765));
 \end{codeblock}
-since the values for \tcode{a} and \tcode{b} might have been,
+since the values for \tcode{a} and \tcode{b} can be,
 respectively, 4 and $-8$ or $-17$ and 12. However on a machine in which
 overflows do not produce an exception and in which the results of
 overflows are reversible, the above expression statement can be
@@ -173,7 +173,7 @@
 \pnum
 \begin{note}
 Historically, lvalues and rvalues were so-called
-because they could appear on the left- and right-hand side of an assignment
+because they appeared on the left- and right-hand side of an assignment
 (although this is no longer generally true);
 glvalues are ``generalized'' lvalues,
 prvalues are ``pure'' rvalues,
@@ -262,7 +262,7 @@
 \begin{note}
 There are no prvalue bit-fields; if a bit-field is converted to a
 prvalue\iref{conv.lval}, a prvalue of the type of the bit-field is
-created, which might then be promoted\iref{conv.prom}.
+created, which can then be promoted\iref{conv.prom}.
 \end{note}
 
 \pnum
@@ -787,10 +787,10 @@
 can be converted to type \tcode{T2}
 if the qualification-combined type of \tcode{T1} and \tcode{T2} is \tcode{T2}.
 \begin{note}
-If a program could assign a pointer of type \tcode{T**} to a pointer of
+If a program were able to assign a pointer of type \tcode{T**} to a pointer of
 type \keyword{const} \tcode{T**} (that is, if line \#1 below were
-allowed), a program could inadvertently modify a const object
-(as it is done on line \#2). For example,
+allowed), it would be possible for a const object to be inadvertently modified
+(as is done on line \#2). For example,
 \begin{codeblock}
 int main() {
   const char c = 'c';
@@ -4197,7 +4197,7 @@
 
 \pnum
 \begin{note}
-The mapping performed by \keyword{reinterpret_cast} might, or might not, produce a
+The mapping performed by \keyword{reinterpret_cast} can produce a
 representation different from the original value.
 \end{note}
 
@@ -6922,8 +6922,8 @@
 and the converted operand is used in place of the original operand for
 the remainder of this subclause.
 \begin{note}
-The conversion might be ill-formed even if an implicit conversion
-sequence could be formed.
+It is possible for the conversion to be ill-formed even if an implicit conversion
+sequence can be formed.
 \end{note}
 
 \pnum