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Definition df-fun 4142
Description: Define a function. Definition 10.1 of [Quine] p. 65. For alternate definitions, see dffun2 4567, dffun3 4568, dffun4 4569, dffun5 4570, dffun6 4572, dffun7 4582, dffun8 4583, and dffun9 4584.
Assertion
Ref Expression
df-fun |- (Fun A <-> (Rel A /\ (A o. `'A) C_ _I ))

Detailed syntax breakdown of Definition df-fun
StepHypRef Expression
1 cA . . 3 class A
21wfun 4126 . 2 wff Fun A
31wrel 4125 . . 3 wff Rel A
41ccnv 4119 . . . . 5 class `'A
51, 4ccom 4124 . . . 4 class (A o. `'A)
6 cid 3744 . . . 4 class _I
75, 6wss 2784 . . 3 wff (A o. `'A) C_ _I
83, 7wa 412 . 2 wff (Rel A /\ (A o. `'A) C_ _I )
92, 8wb 203 1 wff (Fun A <-> (Rel A /\ (A o. `'A) C_ _I ))
Colors of variables: wff set class
This definition is referenced by:  dffun2 4567  funrel 4574  hbfun 4579  funi 4586  f1ococnv2 4780  dffv2 4856  flimfnei2 15684  cnvcan 16610
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