mention narrowing complex and native types

Author: TimToady

S32-setting-library/Numeric.pod

@@ -212,7 +212,8 @@ Convert from radians to C<$base>.
 Attempts to coerce the number to the narrowest type that can represent it accurately;
 for instance, a C<Rat> with a denominator of 1 maybe be coerced to an C<Int> instead;
 an integral C<Num> may likewise turn into an C<Int>.  (Neither C<Num> nor C<Rat> convert
-to each other, however.)
+to each other, however.)  C<Complex> with a 0 imaginary part may narrow to a C<Real> type.
+Conjecturally, wide native types could narrow to narrower native types.
 
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