| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | edgval 29066 | . . . . 5
⊢
(Edg‘𝐺) = ran
(iEdg‘𝐺) | 
| 2 | 1 | a1i 11 | . . . 4
⊢ (𝐺 ∈ UPGraph →
(Edg‘𝐺) = ran
(iEdg‘𝐺)) | 
| 3 | 2 | eleq2d 2827 | . . 3
⊢ (𝐺 ∈ UPGraph → (𝐸 ∈ (Edg‘𝐺) ↔ 𝐸 ∈ ran (iEdg‘𝐺))) | 
| 4 |  | eqid 2737 | . . . . . . 7
⊢
(Vtx‘𝐺) =
(Vtx‘𝐺) | 
| 5 |  | eqid 2737 | . . . . . . 7
⊢
(iEdg‘𝐺) =
(iEdg‘𝐺) | 
| 6 | 4, 5 | upgrf 29103 | . . . . . 6
⊢ (𝐺 ∈ UPGraph →
(iEdg‘𝐺):dom
(iEdg‘𝐺)⟶{𝑥 ∈ (𝒫 (Vtx‘𝐺) ∖ {∅}) ∣
(♯‘𝑥) ≤
2}) | 
| 7 | 6 | frnd 6744 | . . . . 5
⊢ (𝐺 ∈ UPGraph → ran
(iEdg‘𝐺) ⊆
{𝑥 ∈ (𝒫
(Vtx‘𝐺) ∖
{∅}) ∣ (♯‘𝑥) ≤ 2}) | 
| 8 | 7 | sseld 3982 | . . . 4
⊢ (𝐺 ∈ UPGraph → (𝐸 ∈ ran (iEdg‘𝐺) → 𝐸 ∈ {𝑥 ∈ (𝒫 (Vtx‘𝐺) ∖ {∅}) ∣
(♯‘𝑥) ≤
2})) | 
| 9 |  | fveq2 6906 | . . . . . . 7
⊢ (𝑥 = 𝐸 → (♯‘𝑥) = (♯‘𝐸)) | 
| 10 | 9 | breq1d 5153 | . . . . . 6
⊢ (𝑥 = 𝐸 → ((♯‘𝑥) ≤ 2 ↔ (♯‘𝐸) ≤ 2)) | 
| 11 | 10 | elrab 3692 | . . . . 5
⊢ (𝐸 ∈ {𝑥 ∈ (𝒫 (Vtx‘𝐺) ∖ {∅}) ∣
(♯‘𝑥) ≤ 2}
↔ (𝐸 ∈ (𝒫
(Vtx‘𝐺) ∖
{∅}) ∧ (♯‘𝐸) ≤ 2)) | 
| 12 |  | eldifsn 4786 | . . . . . . . . 9
⊢ (𝐸 ∈ (𝒫
(Vtx‘𝐺) ∖
{∅}) ↔ (𝐸 ∈
𝒫 (Vtx‘𝐺)
∧ 𝐸 ≠
∅)) | 
| 13 | 12 | biimpi 216 | . . . . . . . 8
⊢ (𝐸 ∈ (𝒫
(Vtx‘𝐺) ∖
{∅}) → (𝐸 ∈
𝒫 (Vtx‘𝐺)
∧ 𝐸 ≠
∅)) | 
| 14 | 13 | anim1i 615 | . . . . . . 7
⊢ ((𝐸 ∈ (𝒫
(Vtx‘𝐺) ∖
{∅}) ∧ (♯‘𝐸) ≤ 2) → ((𝐸 ∈ 𝒫 (Vtx‘𝐺) ∧ 𝐸 ≠ ∅) ∧ (♯‘𝐸) ≤ 2)) | 
| 15 |  | df-3an 1089 | . . . . . . 7
⊢ ((𝐸 ∈ 𝒫
(Vtx‘𝐺) ∧ 𝐸 ≠ ∅ ∧
(♯‘𝐸) ≤ 2)
↔ ((𝐸 ∈ 𝒫
(Vtx‘𝐺) ∧ 𝐸 ≠ ∅) ∧
(♯‘𝐸) ≤
2)) | 
| 16 | 14, 15 | sylibr 234 | . . . . . 6
⊢ ((𝐸 ∈ (𝒫
(Vtx‘𝐺) ∖
{∅}) ∧ (♯‘𝐸) ≤ 2) → (𝐸 ∈ 𝒫 (Vtx‘𝐺) ∧ 𝐸 ≠ ∅ ∧ (♯‘𝐸) ≤ 2)) | 
| 17 | 16 | a1i 11 | . . . . 5
⊢ (𝐺 ∈ UPGraph → ((𝐸 ∈ (𝒫
(Vtx‘𝐺) ∖
{∅}) ∧ (♯‘𝐸) ≤ 2) → (𝐸 ∈ 𝒫 (Vtx‘𝐺) ∧ 𝐸 ≠ ∅ ∧ (♯‘𝐸) ≤ 2))) | 
| 18 | 11, 17 | biimtrid 242 | . . . 4
⊢ (𝐺 ∈ UPGraph → (𝐸 ∈ {𝑥 ∈ (𝒫 (Vtx‘𝐺) ∖ {∅}) ∣
(♯‘𝑥) ≤ 2}
→ (𝐸 ∈ 𝒫
(Vtx‘𝐺) ∧ 𝐸 ≠ ∅ ∧
(♯‘𝐸) ≤
2))) | 
| 19 | 8, 18 | syld 47 | . . 3
⊢ (𝐺 ∈ UPGraph → (𝐸 ∈ ran (iEdg‘𝐺) → (𝐸 ∈ 𝒫 (Vtx‘𝐺) ∧ 𝐸 ≠ ∅ ∧ (♯‘𝐸) ≤ 2))) | 
| 20 | 3, 19 | sylbid 240 | . 2
⊢ (𝐺 ∈ UPGraph → (𝐸 ∈ (Edg‘𝐺) → (𝐸 ∈ 𝒫 (Vtx‘𝐺) ∧ 𝐸 ≠ ∅ ∧ (♯‘𝐸) ≤ 2))) | 
| 21 | 20 | imp 406 | 1
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 ∈ (Edg‘𝐺)) → (𝐸 ∈ 𝒫 (Vtx‘𝐺) ∧ 𝐸 ≠ ∅ ∧ (♯‘𝐸) ≤ 2)) |