Auf dieser Seite haben wir wichtige Formeln der Mengenlehre für dich aufgelistet. Die Beweise findest du in den folgenden Kapiteln:
![{\displaystyle \left(A\cap B\right)\cap C=A\cap \left(B\cap C\right)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5b80f0799b2a27e4fe75e07fb469aa8904080077)
![{\displaystyle \left(A\cup B\right)\cup C=A\cup \left(B\cup C\right)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/a3b5269074379e0be1cc0b685ee6ab72c363ab58)
![{\displaystyle \left(A\,\triangle \,B\right)\,\triangle \,C=A\,\triangle \,\left(B\,\triangle \,C\right)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d196b466b6823655467c14e0a2bc8e9be7faa7b5)
![{\displaystyle A\cap B=B\cap A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c9192707b022c63da4833c865e2ce5c7ced05860)
![{\displaystyle A\cup B=B\cup A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e5fdb5dfc00d1e5850310af370e406c817267287)
![{\displaystyle A\,\triangle \,B=B\,\triangle \,A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/b3fe37f00c12190bd39d984659be61fd14d399a8)
![{\displaystyle A\cap (B\cup C)=(A\cap B)\cup (A\cap C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5a93af5a9e180fd33a3198837d1e4a340d09c65d)
![{\displaystyle A\cup (B\cap C)=(A\cup B)\cap (A\cup C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e56cf51b2af5f5c0fb30790af2fa2f4a04ff9777)
![{\displaystyle A\cap (B\,\triangle \,C)=(A\cap B)\,\triangle \,(A\cap C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/339ce78a8a0d48e8997cc23c8517416d8d18eda5)
![{\displaystyle A\cap A=A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/b1aed554bbe8370230d848e7d1900dccb87b972e)
![{\displaystyle A\cup A=A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/44ea1c5050f5f3330d56565bff328f42a819e9f8)
![{\displaystyle A\cap (A\cup B)=A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/da2cf46f728500a3dd203690e54bc0b021a32047)
![{\displaystyle A\cup (A\cap B)=A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f0dae78850c5e93789cea0dc6796f98e748ef69f)
Im Folgenden sei
die Grundmenge.
![{\displaystyle A\cap M=A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/dce709ebff2c7e0b496a161f324383bf114695c4)
![{\displaystyle A\cup \varnothing =A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1fc75e355940ce952b6fdcf9146a88bebcb59f23)
![{\displaystyle A\,\triangle \,\varnothing =A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e8764bbee556da1691a473be724a3b5b284e2e33)
Im Folgenden sei
die Grundmenge.
![{\displaystyle A\cup M=M}](https://wikimedia.org/api/rest_v1/media/math/render/svg/21090a06bc605689233429660f32637980c04951)
![{\displaystyle A\cap \varnothing =\varnothing }](https://wikimedia.org/api/rest_v1/media/math/render/svg/8ffa61a78743addd6131fd3be42df3303418352f)
![{\displaystyle (A\cap B)^{\complement }=A^{\complement }\cup B^{\complement }}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f95470d591c8f7e36df94ef1803815bb4b4d98a3)
![{\displaystyle (A\cup B)^{\complement }=A^{\complement }\cap B^{\complement }}](https://wikimedia.org/api/rest_v1/media/math/render/svg/67ee8f8573dcd4ea9154e7748d21af057d739e9e)
Im Folgenden sei
die Grundmenge.
![{\displaystyle (A^{\complement })^{\complement }=A}](https://wikimedia.org/api/rest_v1/media/math/render/svg/71b8e8141805389e4b1a421611ee13e8739b4663)
![{\displaystyle M^{\complement }=\varnothing }](https://wikimedia.org/api/rest_v1/media/math/render/svg/cc9283eed84ce95d2bb4a05860dc87cdc2940a95)
![{\displaystyle \varnothing ^{\complement }=M}](https://wikimedia.org/api/rest_v1/media/math/render/svg/b4eea1599647621f09d5c446893b55b8654b2fff)
![{\displaystyle A\cap A^{\complement }=\varnothing }](https://wikimedia.org/api/rest_v1/media/math/render/svg/ccbe3ff2f0f20220ff2a3c1cd8cc43cdc2ee5178)
![{\displaystyle A\cup A^{\complement }=M}](https://wikimedia.org/api/rest_v1/media/math/render/svg/a874163ec424221f23b7f280b146818b94928635)
![{\displaystyle A\,\triangle \,M=A^{\complement }}](https://wikimedia.org/api/rest_v1/media/math/render/svg/08c1a312c4a09ad57560f55865eca508cd018f1a)
![{\displaystyle A\,\triangle \,A^{\complement }=M}](https://wikimedia.org/api/rest_v1/media/math/render/svg/969636db2a677489062c63d4d2e5834056939ac4)
![{\displaystyle (A\setminus B)\setminus C=A\setminus (B\cup C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f7d4efbfd7a63ba3062f3fbda68a36ac20ecea49)
![{\displaystyle A\setminus (B\setminus C)=(A\setminus B)\cup (A\cap C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e6b509237e8968cfc76d56cf7661709c014ee418)
![{\displaystyle (A\cap B)\setminus C=(A\setminus C)\cap (B\setminus C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/593d4063413d9d9686be95919706e046121212da)
![{\displaystyle (A\cup B)\setminus C=(A\setminus C)\cup (B\setminus C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/36b888be0500c7e6cf1f82b806fc7415fa0c6dec)
![{\displaystyle A\setminus (B\cap C)=(A\setminus B)\cup (A\setminus C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/9ad16772dbc38576aa521b69205e72af74fc975d)
![{\displaystyle A\setminus (B\cup C)=(A\setminus B)\cap (A\setminus C)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3a6eec34036c269c1d841f48e1706692a6c9b1ff)
Es gelten Assoziativität, Kommutativität, Distributivität und Neutralität, siehe dort.
![{\displaystyle A\,\triangle \,A=\varnothing }](https://wikimedia.org/api/rest_v1/media/math/render/svg/3e040dfa897e3df9848f442bb7562a8a099fee6f)
![{\displaystyle A\triangle B=(A\cup B)\setminus (A\cap B)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/51220d74568bb498de244dd1732912281f5da672)
![{\displaystyle A\triangle B=(A\setminus B)\cup (B\setminus A)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d41abee74516e83204ae2c2ee449f2ebb5f2befd)
![{\displaystyle (A\triangle B)^{\complement }=(A^{\complement }\cap B^{\complement })\cup (A\cap B)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c121b0939d5a1c0abc162dce852c52a71542eeef)