Description: Alternate proof of upgr0eop , using the general theorem gropeld to transform a theorem for an arbitrary representation of a graph into a theorem for a graph represented as ordered pair. This general approach causes some overhead, which makes the proof longer than necessary (see proof of upgr0eop ). (Contributed by AV, 11-Oct-2020) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | upgr0eopALT | ⊢ ( 𝑉 ∈ 𝑊 → 〈 𝑉 , ∅ 〉 ∈ UPGraph ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | vex | ⊢ 𝑔 ∈ V | |
2 | 1 | a1i | ⊢ ( ( ( Vtx ‘ 𝑔 ) = 𝑉 ∧ ( iEdg ‘ 𝑔 ) = ∅ ) → 𝑔 ∈ V ) |
3 | simpr | ⊢ ( ( ( Vtx ‘ 𝑔 ) = 𝑉 ∧ ( iEdg ‘ 𝑔 ) = ∅ ) → ( iEdg ‘ 𝑔 ) = ∅ ) | |
4 | 2 3 | upgr0e | ⊢ ( ( ( Vtx ‘ 𝑔 ) = 𝑉 ∧ ( iEdg ‘ 𝑔 ) = ∅ ) → 𝑔 ∈ UPGraph ) |
5 | 4 | ax-gen | ⊢ ∀ 𝑔 ( ( ( Vtx ‘ 𝑔 ) = 𝑉 ∧ ( iEdg ‘ 𝑔 ) = ∅ ) → 𝑔 ∈ UPGraph ) |
6 | 5 | a1i | ⊢ ( 𝑉 ∈ 𝑊 → ∀ 𝑔 ( ( ( Vtx ‘ 𝑔 ) = 𝑉 ∧ ( iEdg ‘ 𝑔 ) = ∅ ) → 𝑔 ∈ UPGraph ) ) |
7 | id | ⊢ ( 𝑉 ∈ 𝑊 → 𝑉 ∈ 𝑊 ) | |
8 | 0ex | ⊢ ∅ ∈ V | |
9 | 8 | a1i | ⊢ ( 𝑉 ∈ 𝑊 → ∅ ∈ V ) |
10 | 6 7 9 | gropeld | ⊢ ( 𝑉 ∈ 𝑊 → 〈 𝑉 , ∅ 〉 ∈ UPGraph ) |