Metamath Proof Explorer


Definition df-acycgr

Description: Define the class of all acyclic graphs. A graph is calledacyclic if it has no (non-trivial) cycles. (Contributed by BTernaryTau, 11-Oct-2023)

Ref Expression
Assertion df-acycgr
|- AcyclicGraph = { g | -. E. f E. p ( f ( Cycles ` g ) p /\ f =/= (/) ) }

Detailed syntax breakdown

Step Hyp Ref Expression
0 cacycgr
 |-  AcyclicGraph
1 vg
 |-  g
2 vf
 |-  f
3 vp
 |-  p
4 2 cv
 |-  f
5 ccycls
 |-  Cycles
6 1 cv
 |-  g
7 6 5 cfv
 |-  ( Cycles ` g )
8 3 cv
 |-  p
9 4 8 7 wbr
 |-  f ( Cycles ` g ) p
10 c0
 |-  (/)
11 4 10 wne
 |-  f =/= (/)
12 9 11 wa
 |-  ( f ( Cycles ` g ) p /\ f =/= (/) )
13 12 3 wex
 |-  E. p ( f ( Cycles ` g ) p /\ f =/= (/) )
14 13 2 wex
 |-  E. f E. p ( f ( Cycles ` g ) p /\ f =/= (/) )
15 14 wn
 |-  -. E. f E. p ( f ( Cycles ` g ) p /\ f =/= (/) )
16 15 1 cab
 |-  { g | -. E. f E. p ( f ( Cycles ` g ) p /\ f =/= (/) ) }
17 0 16 wceq
 |-  AcyclicGraph = { g | -. E. f E. p ( f ( Cycles ` g ) p /\ f =/= (/) ) }