doc/guide/src/ImperativeTypeVariable.adoc

   1 ImperativeTypeVariable
   2 ======================
   3
   4 In <:StandardML:Standard ML>, an imperative type variable is a type
   5 variable whose second character is a digit, as in `'1a` or
   6 `'2b`.  Imperative type variables were used as an alternative to
   7 the <:ValueRestriction:> in an earlier version of SML, but no longer play
   8 a role.  They are treated exactly as other type variables.