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Metamath Proof Explorer

Theorem uspgrupgr

Description: A simple pseudograph is an undirected pseudograph. (Contributed by Alexander van der Vekens, 10-Aug-2017) (Revised by AV, 15-Oct-2020)

Ref Expression
Assertion uspgrupgr 
|- ( G e. USPGraph -> G e. UPGraph )

Proof

Step Hyp Ref Expression
1 eqid 
 |-  ( Vtx ` G ) = ( Vtx ` G )
2 eqid 
 |-  ( iEdg ` G ) = ( iEdg ` G )
3 1 2 isuspgr 
 |-  ( G e. USPGraph -> ( G e. USPGraph <-> ( iEdg ` G ) : dom ( iEdg ` G ) -1-1-> { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) )
4 f1f 
 |-  ( ( 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 } )
5 3 4 biimtrdi 
 |-  ( G e. USPGraph -> ( G e. USPGraph -> ( iEdg ` G ) : dom ( iEdg ` G ) --> { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) )
6 1 2 isupgr 
 |-  ( G e. USPGraph -> ( G e. UPGraph <-> ( iEdg ` G ) : dom ( iEdg ` G ) --> { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) )
7 5 6 sylibrd 
 |-  ( G e. USPGraph -> ( G e. USPGraph -> G e. UPGraph ) )
8 7 pm2.43i 
 |-  ( G e. USPGraph -> G e. UPGraph )