This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Metamath Proof Explorer
Description: The subset class is a binary relation. (Contributed by Scott Fenton, 31-Mar-2012)
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|
Ref |
Expression |
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Assertion |
relsset |
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Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
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df-sset |
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| 2 |
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difss |
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| 3 |
1 2
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eqsstri |
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| 4 |
|
df-rel |
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| 5 |
3 4
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mpbir |
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