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 | ¬ ∃ f ∃ p f Cycles ⁡ g p ∧ f ≠ ∅

Detailed syntax breakdown

Step Hyp Ref Expression
0 cacycgr class AcyclicGraph
1 vg setvar g
2 vf setvar f
3 vp setvar p
4 2 cv setvar f
5 ccycls class Cycles
6 1 cv setvar g
7 6 5 cfv class Cycles ⁡ g
8 3 cv setvar p
9 4 8 7 wbr wff f Cycles ⁡ g p
10 c0 class ∅
11 4 10 wne wff f ≠ ∅
12 9 11 wa wff f Cycles ⁡ g p ∧ f ≠ ∅
13 12 3 wex wff ∃ p f Cycles ⁡ g p ∧ f ≠ ∅
14 13 2 wex wff ∃ f ∃ p f Cycles ⁡ g p ∧ f ≠ ∅
15 14 wn wff ¬ ∃ f ∃ p f Cycles ⁡ g p ∧ f ≠ ∅
16 15 1 cab class g | ¬ ∃ f ∃ p f Cycles ⁡ g p ∧ f ≠ ∅
17 0 16 wceq wff AcyclicGraph = g | ¬ ∃ f ∃ p f Cycles ⁡ g p ∧ f ≠ ∅