**Description:** A positive integer is nonzero. (Contributed by Mario Carneiro, 27-May-2016)

Ref | Expression | ||
---|---|---|---|

Hypothesis | nnge1d.1 | $${\u22a2}{\phi}\to {A}\in \mathbb{N}$$ | |

Assertion | nnne0d | $${\u22a2}{\phi}\to {A}\ne 0$$ |

Step | Hyp | Ref | Expression |
---|---|---|---|

1 | nnge1d.1 | $${\u22a2}{\phi}\to {A}\in \mathbb{N}$$ | |

2 | nnne0 | $${\u22a2}{A}\in \mathbb{N}\to {A}\ne 0$$ | |

3 | 1 2 | syl | $${\u22a2}{\phi}\to {A}\ne 0$$ |