Combinatory Categorical Grammar (CCG) Supertagging is a sequence tagging task in NLP. The standard parsing model of Clark and Curran (2007) uses over $400$ lexical categories (or supertags), compared to about $50$ part-of-speech (POS) tags for typical context-free grammar (CFG) parsers (Xu et al., 2017). As an example, take the following sequence of tokens as an input: [I, saw, squirrels, with, nuts], with output: [NP, (S\NP)/NP, NP, (NP\NP)/NP, NP].