Metamath Proof Explorer


Theorem subgrpth

Description: If a path exists in a subgraph of a graph G , then that path also exists in G . (Contributed by BTernaryTau, 22-Oct-2023)

Ref Expression
Assertion subgrpth ⊢ S SubGraph G → F Paths ⁡ S P → F Paths ⁡ G P

Proof

Step Hyp Ref Expression
1 subgrtrl ⊢ S SubGraph G → F Trails ⁡ S P → F Trails ⁡ G P
2 idd ⊢ S SubGraph G → Fun ⁡ P ↾ 1 ..^ F -1 → Fun ⁡ P ↾ 1 ..^ F -1
3 idd ⊢ S SubGraph G → P 0 F ∩ P 1 ..^ F = ∅ → P 0 F ∩ P 1 ..^ F = ∅
4 1 2 3 3anim123d ⊢ S SubGraph G → F Trails ⁡ S P ∧ Fun ⁡ P ↾ 1 ..^ F -1 ∧ P 0 F ∩ P 1 ..^ F = ∅ → F Trails ⁡ G P ∧ Fun ⁡ P ↾ 1 ..^ F -1 ∧ P 0 F ∩ P 1 ..^ F = ∅
5 ispth ⊢ F Paths ⁡ S P ↔ F Trails ⁡ S P ∧ Fun ⁡ P ↾ 1 ..^ F -1 ∧ P 0 F ∩ P 1 ..^ F = ∅
6 ispth ⊢ F Paths ⁡ G P ↔ F Trails ⁡ G P ∧ Fun ⁡ P ↾ 1 ..^ F -1 ∧ P 0 F ∩ P 1 ..^ F = ∅
7 4 5 6 3imtr4g ⊢ S SubGraph G → F Paths ⁡ S P → F Paths ⁡ G P