| Step | Hyp | Ref | Expression | 
						
							| 1 |  | uspgrupgr |  |-  ( G e. USPGraph -> G e. UPGraph ) | 
						
							| 2 |  | uspgrushgr |  |-  ( G e. USPGraph -> G e. USHGraph ) | 
						
							| 3 | 1 2 | jca |  |-  ( G e. USPGraph -> ( G e. UPGraph /\ G e. USHGraph ) ) | 
						
							| 4 |  | eqid |  |-  ( Vtx ` G ) = ( Vtx ` G ) | 
						
							| 5 |  | eqid |  |-  ( iEdg ` G ) = ( iEdg ` G ) | 
						
							| 6 | 4 5 | ushgrf |  |-  ( G e. USHGraph -> ( iEdg ` G ) : dom ( iEdg ` G ) -1-1-> ( ~P ( Vtx ` G ) \ { (/) } ) ) | 
						
							| 7 |  | edgval |  |-  ( Edg ` G ) = ran ( iEdg ` G ) | 
						
							| 8 |  | upgredgss |  |-  ( G e. UPGraph -> ( Edg ` G ) C_ { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) | 
						
							| 9 | 7 8 | eqsstrrid |  |-  ( G e. UPGraph -> ran ( iEdg ` G ) C_ { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) | 
						
							| 10 |  | f1ssr |  |-  ( ( ( iEdg ` G ) : dom ( iEdg ` G ) -1-1-> ( ~P ( Vtx ` G ) \ { (/) } ) /\ ran ( iEdg ` G ) C_ { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) -> ( iEdg ` G ) : dom ( iEdg ` G ) -1-1-> { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) | 
						
							| 11 | 6 9 10 | syl2anr |  |-  ( ( G e. UPGraph /\ G e. USHGraph ) -> ( iEdg ` G ) : dom ( iEdg ` G ) -1-1-> { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) | 
						
							| 12 | 4 5 | isuspgr |  |-  ( G e. UPGraph -> ( G e. USPGraph <-> ( iEdg ` G ) : dom ( iEdg ` G ) -1-1-> { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) ) | 
						
							| 13 | 12 | adantr |  |-  ( ( G e. UPGraph /\ G e. USHGraph ) -> ( G e. USPGraph <-> ( iEdg ` G ) : dom ( iEdg ` G ) -1-1-> { x e. ( ~P ( Vtx ` G ) \ { (/) } ) | ( # ` x ) <_ 2 } ) ) | 
						
							| 14 | 11 13 | mpbird |  |-  ( ( G e. UPGraph /\ G e. USHGraph ) -> G e. USPGraph ) | 
						
							| 15 | 3 14 | impbii |  |-  ( G e. USPGraph <-> ( G e. UPGraph /\ G e. USHGraph ) ) |