Symbol | Name | Explanation |

{ , } | keys | the set of… Ex: {a, b, c} represents the set composed of a, b and c. |

{} or | empty set | It means that the set has no elements, it is an empty set. Ex: THE B = |

for all | It means "For all" or "For whatever". Ex: x> 0, x is positive. It means that for any x greater than 0, x is positive. | |

belongs | Indicates relevance relationship. Ex: 5 N. It means that 5 belongs to the natural numbers. | |

does not belong | Does not belong . Ex: -1 N. Means that the number -1 does not belong to the natural numbers. | |

exist | Indicates existence. Ex: It means that there is an x belonging to the set of integers such that x is greater than 3. | |

is contained | Ex: N Z, that is, the set of natural numbers is contained in the set of integers. | |

not contained | Ex: R N, that is, the set of real numbers is not contained in the set of natural numbers. | |

contains | Ex: Z N, that is, the set of integers contains the set of natural numbers. | |

if then | if then Q: Jose goes to the market Pwhat If Joseph goes to the market then he goes shopping. | |

if and only if | if and only if Ex: Pwhat Maria goes to the beach if and only if she gets good grades. | |

THE B | union of sets | Reads as "The Union B" Ex: THE B = {3,5,6,7,8,10} |

THE B | set intersection | Reads as "A Intersection B" Ex: A = {1,3,5,7,8,10} THE B = {3,7,8} |

A - B | sets difference | It is read as "difference from A to B". Is the set of all elements that belong to set A Ex: A-B = {X | xThe ex B} |