Question Number 11419 by fadim727 last updated on 25/Mar/17
$$\mathrm{If}\:\mathrm{A}\:=\:\left\{\mathrm{whole}\:\mathrm{numbers}\right\}\:\mathrm{and}\: \\ $$$$\mathrm{B}=\left\{\mathrm{natural}\:\mathrm{numbers}\right\},\:\mathrm{then}\:\mathrm{A}\bigtriangleup\mathrm{B}=\_\_\_. \\ $$
Commented by FilupS last updated on 26/Mar/17
$$\mathrm{whole}\:\mathrm{numbers}\:=\:\mathbb{Z}\:=\:\left\{...,\:−\mathrm{2},\:−\mathrm{1},\:\mathrm{0},\:\mathrm{1},\:\mathrm{2},\:...\right\} \\ $$$$\mathrm{natural}\:\mathrm{numbers}\:=\:\mathbb{N}\:=\:\left\{\mathrm{1},\:\mathrm{2},\:...\right\} \\ $$$$\: \\ $$$${A}=\mathbb{Z},\:{B}=\mathbb{N} \\ $$$$\mathrm{if}\:\:{A}\bigtriangleup{B}\:\:\mathrm{means}\:\:{A}\wedge{B},\:\:\mathrm{or}\:\:{A}\cap{B},\:\:\mathrm{then}: \\ $$$${A}\cap{B}=\mathbb{Z} \\ $$