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 ⊢ 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 ⊢ ∃ 𝑝 ( 𝑓 ( Cycles ‘ 𝑔 ) 𝑝 ∧ 𝑓 ≠ ∅ )
14 13 2 wex ⊢ ∃ 𝑓 ∃ 𝑝 ( 𝑓 ( Cycles ‘ 𝑔 ) 𝑝 ∧ 𝑓 ≠ ∅ )
15 14 wn ⊢ ¬ ∃ 𝑓 ∃ 𝑝 ( 𝑓 ( Cycles ‘ 𝑔 ) 𝑝 ∧ 𝑓 ≠ ∅ )
16 15 1 cab ⊢ { 𝑔 ∣ ¬ ∃ 𝑓 ∃ 𝑝 ( 𝑓 ( Cycles ‘ 𝑔 ) 𝑝 ∧ 𝑓 ≠ ∅ ) }
17 0 16 wceq ⊢ AcyclicGraph = { 𝑔 ∣ ¬ ∃ 𝑓 ∃ 𝑝 ( 𝑓 ( Cycles ‘ 𝑔 ) 𝑝 ∧ 𝑓 ≠ ∅ ) }