Metamath Proof Explorer


Theorem fun2dmnopgexmpl

Description: A function with a domain containing (at least) two different elements is not an ordered pair. (Contributed by AV, 21-Sep-2020) (Avoid depending on this detail.)

Ref Expression
Assertion fun2dmnopgexmpl ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ¬ 𝐺 ∈ ( V × V ) )

Proof

Step Hyp Ref Expression
1 0ne1 ⊢ 0 ≠ 1
2 1 neii ⊢ ¬ 0 = 1
3 2 intnanr ⊢ ¬ ( 0 = 1 ∧ 𝑎 = { 0 } )
4 3 intnanr ⊢ ¬ ( ( 0 = 1 ∧ 𝑎 = { 0 } ) ∧ ( ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ∨ ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ) )
5 4 gen2 ⊢ ∀ 𝑎 ∀ 𝑏 ¬ ( ( 0 = 1 ∧ 𝑎 = { 0 } ) ∧ ( ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ∨ ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ) )
6 eqeq1 ⊢ ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ( 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ ↔ { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } = ⟨ 𝑎 , 𝑏 ⟩ ) )
7 c0ex ⊢ 0 ∈ V
8 1ex ⊢ 1 ∈ V
9 vex ⊢ 𝑎 ∈ V
10 vex ⊢ 𝑏 ∈ V
11 7 8 8 8 9 10 propeqop ⊢ ( { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } = ⟨ 𝑎 , 𝑏 ⟩ ↔ ( ( 0 = 1 ∧ 𝑎 = { 0 } ) ∧ ( ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ∨ ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ) ) )
12 6 11 bitrdi ⊢ ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ( 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ ↔ ( ( 0 = 1 ∧ 𝑎 = { 0 } ) ∧ ( ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ∨ ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ) ) ) )
13 12 notbid ⊢ ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ( ¬ 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ ↔ ¬ ( ( 0 = 1 ∧ 𝑎 = { 0 } ) ∧ ( ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ∨ ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ) ) ) )
14 13 2albidv ⊢ ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ( ∀ 𝑎 ∀ 𝑏 ¬ 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ ↔ ∀ 𝑎 ∀ 𝑏 ¬ ( ( 0 = 1 ∧ 𝑎 = { 0 } ) ∧ ( ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ∨ ( 0 = 1 ∧ 𝑏 = { 0 , 1 } ) ) ) ) )
15 5 14 mpbiri ⊢ ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ∀ 𝑎 ∀ 𝑏 ¬ 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ )
16 2nexaln ⊢ ( ¬ ∃ 𝑎 ∃ 𝑏 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ ↔ ∀ 𝑎 ∀ 𝑏 ¬ 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ )
17 15 16 sylibr ⊢ ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ¬ ∃ 𝑎 ∃ 𝑏 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ )
18 elvv ⊢ ( 𝐺 ∈ ( V × V ) ↔ ∃ 𝑎 ∃ 𝑏 𝐺 = ⟨ 𝑎 , 𝑏 ⟩ )
19 17 18 sylnibr ⊢ ( 𝐺 = { ⟨ 0 , 1 ⟩ , ⟨ 1 , 1 ⟩ } → ¬ 𝐺 ∈ ( V × V ) )