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Definition df-fun 4026
Description: Define a function. Definition 10.1 of [Quine] p. 65. For alternate definitions, see dffun2 4456, dffun3 4457, dffun4 4458, dffun5 4459, dffun6 4461, dffun7 4471, dffun8 4472, and dffun9 4473.
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 4010 . 2 wff Fun A
31wrel 4009 . . 3 wff Rel A
41ccnv 4003 . . . . 5 class `'A
51, 4ccom 4008 . . . 4 class (A o. `'A)
6 cid 3620 . . . 4 class _I
75, 6wss 2657 . . 3 wff (A o. `'A) C_ _I
83, 7wa 377 . 2 wff (Rel A /\ (A o. `'A) C_ _I )
92, 8wb 184 1 wff (Fun A <-> (Rel A /\ (A o. `'A) C_ _I ))
Colors of variables: wff set class
This definition is referenced by:  dffun2 4456  funrel 4463  funss 4464  hbfun 4468  funi 4475  f1ococnv2 4662  dffv2 4739  flimfnei2 16109  cnvcan 17043
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