 Finally, it should be mentioned that there are some who propose mixed approaches, wherein some pronouns are treated as dynamically bound variables whereas others are treated as D-type (see Chierchia 1995; Kurafuji 1998, 1999). On these views, some pronouns are ambiguous between the two readings, while others have only the dynamically bound variable or D-type reading. This type of theory avoids many of the problems raised for each type of account, since they use dynamic semantics for the examples most amenable to a dynamic explanation and d-type pronouns for example most amenable to that sort of explanation. However, the theory comes at a considerable theoretical cost in that it predicts a systematic ambiguity in pronouns that is (arguably) not explicitly marked in any language. (See Elbourne 2005 for further criticisms of these views.)