 By far the most popular reason for believing in compositionality is that it works. Linguists have adopted various versions of the principle as a working hypothesis and developed semantic theories on their basis. These theories have provided intuitively satisfactory explanations for certain data, such as the validity or invalidity of inferences or contrasts in acceptability between minimal pairs. Moreover, whenever it was suggested that certain phenomena require abandonment of the principle, it was subsequently shown that this is not so: reasonably elegant and comparatively natural compositional theories were just around the corner; cf.  section 4.2.  