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Mirrors > Home > MPE Home > Th. List > df-1st | Structured version Visualization version Unicode version |
Description: Define a function that
extracts the first member, or abscissa, of an
ordered pair. Theorem op1st 6827 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 6817 |
. 2
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2 | vx |
. . 3
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3 | cvv 3056 |
. . 3
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4 | 2 | cv 1453 |
. . . . . 6
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5 | 4 | csn 3979 |
. . . . 5
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6 | 5 | cdm 4852 |
. . . 4
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7 | 6 | cuni 4211 |
. . 3
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8 | 2, 3, 7 | cmpt 4474 |
. 2
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9 | 1, 8 | wceq 1454 |
1
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Colors of variables: wff setvar class |
This definition is referenced by: 1stval 6821 fo1st 6839 f1stres 6841 |
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