Dual

• Dual (mathematics), a notion of paired concepts that mirror one another • Dual (category theory), a formalization of mathematical duality • see more cases in :Category:Duality (mathematics) • Dual number, a number system used in automatic differentiation • Dual (grammatical number), a grammatical category used in some languages • Dual county, a Gaelic games county which competes in both Gaelic football and hurling • Dual diagnosis, a psychiatric diagnosis of co-occurrence of substance abuse and a mental problem • Dual fertilization, simultaneous application of a P-type and N-type fertilizer • Dual impedance, electrical circuits that are the dual of each other • Dual SIM cellphone supporting use of two SIMs • Aerochute International Dual a two-seat Australian powered parachute design ==Acronyms and other uses==

• Dual (brand), a manufacturer of Hifi equipment • DUAL (cognitive architecture), an artificial intelligence design model • DUAL algorithm, or diffusing update algorithm, used to update Internet protocol routing tables • Dual language, alternative spelling of the Australian Aboriginal Dhuwal language • DUAL table, a special one-row and one-column database table • Dual-Ghia, US-brand of luxury-car of the late 1950s == Media ==

• Dual (2008 film), a 2008 western drama film • Dual (2022 film), a 2022 science fiction thriller film • "Dual" (Heroes), an episode of Heroes • Dual! Parallel Trouble Adventure, an anime series • Dual (album), an album of traditional Scottish and Irish music recorded by Éamonn Doorley, Muireann Nic Amhlaoibh, Julie Fowlis and Ross Martin, released 2008 • Dual (EP), a 2013 EP by Sampha • Duals, an album by U2 • The Duals, American duo • Dual (brand), brand name of audio and video electronics. == People ==

• Duall (c.1795 – c.1840), an Indigenous Australian outlaw and explorer ==See also==