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Theorem umgr0e 26005
Description: The empty graph, with vertices but no edges, is a multigraph. (Contributed by Mario Carneiro, 12-Mar-2015.) (Revised by AV, 25-Nov-2020.)
Hypotheses
Ref Expression
umgr0e.g  |-  ( ph  ->  G  e.  W )
umgr0e.e  |-  ( ph  ->  (iEdg `  G )  =  (/) )
Assertion
Ref Expression
umgr0e  |-  ( ph  ->  G  e. UMGraph  )

Proof of Theorem umgr0e
Dummy variable  x is distinct from all other variables.
StepHypRef Expression
1 umgr0e.e . . . 4  |-  ( ph  ->  (iEdg `  G )  =  (/) )
21f10d 6170 . . 3  |-  ( ph  ->  (iEdg `  G ) : dom  (iEdg `  G
) -1-1-> { x  e.  ( ~P (Vtx `  G
)  \  { (/) } )  |  ( # `  x
)  =  2 } )
3 f1f 6101 . . 3  |-  ( (iEdg `  G ) : dom  (iEdg `  G ) -1-1-> {
x  e.  ( ~P (Vtx `  G )  \  { (/) } )  |  ( # `  x
)  =  2 }  ->  (iEdg `  G
) : dom  (iEdg `  G ) --> { x  e.  ( ~P (Vtx `  G )  \  { (/)
} )  |  (
# `  x )  =  2 } )
42, 3syl 17 . 2  |-  ( ph  ->  (iEdg `  G ) : dom  (iEdg `  G
) --> { x  e.  ( ~P (Vtx `  G )  \  { (/)
} )  |  (
# `  x )  =  2 } )
5 umgr0e.g . . 3  |-  ( ph  ->  G  e.  W )
6 eqid 2622 . . . 4  |-  (Vtx `  G )  =  (Vtx
`  G )
7 eqid 2622 . . . 4  |-  (iEdg `  G )  =  (iEdg `  G )
86, 7isumgr 25990 . . 3  |-  ( G  e.  W  ->  ( G  e. UMGraph  <->  (iEdg `  G ) : dom  (iEdg `  G
) --> { x  e.  ( ~P (Vtx `  G )  \  { (/)
} )  |  (
# `  x )  =  2 } ) )
95, 8syl 17 . 2  |-  ( ph  ->  ( G  e. UMGraph  <->  (iEdg `  G
) : dom  (iEdg `  G ) --> { x  e.  ( ~P (Vtx `  G )  \  { (/)
} )  |  (
# `  x )  =  2 } ) )
104, 9mpbird 247 1  |-  ( ph  ->  G  e. UMGraph  )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    <-> wb 196    = wceq 1483    e. wcel 1990   {crab 2916    \ cdif 3571   (/)c0 3915   ~Pcpw 4158   {csn 4177   dom cdm 5114   -->wf 5884   -1-1->wf1 5885   ` cfv 5888   2c2 11070   #chash 13117  Vtxcvtx 25874  iEdgciedg 25875   UMGraph cumgr 25976
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  ax-pr 4906
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ral 2917  df-rex 2918  df-rab 2921  df-v 3202  df-sbc 3436  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-br 4654  df-opab 4713  df-id 5024  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fv 5896  df-umgr 25978
This theorem is referenced by:  upgr0e  26006
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