Metamath Proof Explorer
Description: Move class substitution inside a negation, in inference form.
(Contributed by Giovanni Mascellani, 27-May-2019)
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Ref |
Expression |
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Hypotheses |
sbcni.1 |
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sbcni.2 |
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Assertion |
sbcni |
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Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
sbcni.1 |
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2 |
|
sbcni.2 |
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3 |
|
sbcng |
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4 |
1 3
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ax-mp |
|
5 |
4 2
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xchbinx |
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