In natural language, however, many predicates appear to be multigrade or variably polyadic; i.e., they can be used with different numbers of arguments, as they can be true of various numbers of things. For example, we say “John is lifting a table”, with “lifting” used as dyadic, as well as “John and Mary are lifting a table”, with “lifting” used as triadic. Moreover, there is a kind of inference, called “argument deletion”, which also suggests that many predicates that prima facie could be assig