1 | initial version |

Shouldn't it return false if the proposition is true and the conclusion false (http://en.wikipedia.org/wiki/Material_conditional)?

Here's how to use it in Sage:

```
sage: f = sage.logic.propcalc.formula('p->q')
sage: f.evaluate({'p':True, 'q':False})
False
```

2 | No.2 Revision |

Hello,

Shouldn't it return false if the proposition is true and the conclusion false (http://en.wikipedia.org/wiki/Material_conditional)?

Here's how to use it in Sage:

```
sage: f = sage.logic.propcalc.formula('p->q')
sage: f.evaluate({'p':True, 'q':False})
False
```

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