ID |
Rule |

1 |
You can use any expression consisting of user ids and operators "& | -". |

2 |
Operator & will show the intersection of the solved problems. A & B will show the problems that are solved by both A and B. |

3 |
Operator | will show the union of the solved problems. A | B will show the problems that are solved by A or by B. |

4 |
Operator - will show the set difference. A - B will show the problems that are solved by A but not by B. |

5 |
You can use parenthesis, i.e. "( )". |

6 |
To get all the problems in LightOJ, use id 0. |

7 |
Precedence order (high to low): () & | -. |