(13) Lexical entries in basic structures must have the thematic roles of their arguments associated with their grammatical functions withouth crossing links between the tiers of Figure 2 [immagine], and with exactly one thematic role linked to SUBJ. Predicates that respect the no-crossing-links provision of (13) may be called "canonical"; those that violate it are "noncanonical".
- Pinker (2004), Pag. 246