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Mirrors > Home > ILE Home > Th. List > df-1st | Unicode version |
Description: Define a function that
extracts the first member, or abscissa, of an
ordered pair. Theorem op1st 5773 proves that it does this. For example,
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Ref | Expression |
---|---|
df-1st |
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Step | Hyp | Ref | Expression |
---|---|---|---|
1 | c1st 5765 |
. 2
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2 | vx |
. . 3
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3 | cvv 2557 |
. . 3
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4 | 2 | cv 1242 |
. . . . . 6
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5 | 4 | csn 3375 |
. . . . 5
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6 | 5 | cdm 4345 |
. . . 4
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7 | 6 | cuni 3580 |
. . 3
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8 | 2, 3, 7 | cmpt 3818 |
. 2
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9 | 1, 8 | wceq 1243 |
1
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Colors of variables: wff set class |
This definition is referenced by: 1stvalg 5769 fo1st 5784 f1stres 5786 |
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