# Points to Remember

- When constructing a flow chart, use the following guidelines:
- Look for a condition that starts the flow.
- Look for an element that occurs in many conditions.
- Keep the chart flexible.

- Be aware of the fallacies associated with the contrapositive:
__cannot__conclude either *Some*means “at least one and perhaps__all__.”- The following statements contain embedded
*if-then*statements.

Statement |
If-then form |

All A’s are B’s. | If x is an A, then x is a B. |

A and B are not both C’s. | If A is a C, then B is not. |

No A is a B. | If A, then not B. |

Only A’s are B’s. | If B, then A. |