## Tags - Part of: [[Logic]] - Related: [[Metamathematics]] [[Meta]] - Includes: - Additional: ## Definitions - First-order [[Logic]] quantifies only variables that range over individuals; second-order logic, also quantifies over [[Set Theory|sets]]; third-order logic also quantifies over sets of sets, and so on. Higher-order logic is the union of first-, second-, third-, ..., nth-order logic; i.e., higher-order logic admits quantification over sets that are nested arbitrarily deeply. ## Main resources - - <iframe src="https://en.wikipedia.org/wiki/Higher-order_logic" allow="fullscreen" allowfullscreen="" style="height:100%;width:100%; aspect-ratio: 16 / 5; "></iframe>