Metamath Proof Explorer


Theorem upgrisupwlkALT

Description: Alternate proof of upgriswlk using the definition of UPGraph and related theorems. (Contributed by AV, 2-Jan-2021) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses upgrisupwlkALT.v 𝑉 = ( Vtx ‘ 𝐺 )
upgrisupwlkALT.i 𝐼 = ( iEdg ‘ 𝐺 )
Assertion upgrisupwlkALT ( ( 𝐺 ∈ UPGraph ∧ 𝐹𝑈𝑃𝑍 ) → ( 𝐹 ( Walks ‘ 𝐺 ) 𝑃 ↔ ( 𝐹 ∈ Word dom 𝐼𝑃 : ( 0 ... ( ♯ ‘ 𝐹 ) ) ⟶ 𝑉 ∧ ∀ 𝑘 ∈ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ( 𝐼 ‘ ( 𝐹𝑘 ) ) = { ( 𝑃𝑘 ) , ( 𝑃 ‘ ( 𝑘 + 1 ) ) } ) ) )

Proof

Step Hyp Ref Expression
1 upgrisupwlkALT.v 𝑉 = ( Vtx ‘ 𝐺 )
2 upgrisupwlkALT.i 𝐼 = ( iEdg ‘ 𝐺 )
3 upgrwlkupwlkb ( 𝐺 ∈ UPGraph → ( 𝐹 ( Walks ‘ 𝐺 ) 𝑃𝐹 ( UPWalks ‘ 𝐺 ) 𝑃 ) )
4 3 3ad2ant1 ( ( 𝐺 ∈ UPGraph ∧ 𝐹𝑈𝑃𝑍 ) → ( 𝐹 ( Walks ‘ 𝐺 ) 𝑃𝐹 ( UPWalks ‘ 𝐺 ) 𝑃 ) )
5 1 2 isupwlk ( ( 𝐺 ∈ UPGraph ∧ 𝐹𝑈𝑃𝑍 ) → ( 𝐹 ( UPWalks ‘ 𝐺 ) 𝑃 ↔ ( 𝐹 ∈ Word dom 𝐼𝑃 : ( 0 ... ( ♯ ‘ 𝐹 ) ) ⟶ 𝑉 ∧ ∀ 𝑘 ∈ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ( 𝐼 ‘ ( 𝐹𝑘 ) ) = { ( 𝑃𝑘 ) , ( 𝑃 ‘ ( 𝑘 + 1 ) ) } ) ) )
6 4 5 bitrd ( ( 𝐺 ∈ UPGraph ∧ 𝐹𝑈𝑃𝑍 ) → ( 𝐹 ( Walks ‘ 𝐺 ) 𝑃 ↔ ( 𝐹 ∈ Word dom 𝐼𝑃 : ( 0 ... ( ♯ ‘ 𝐹 ) ) ⟶ 𝑉 ∧ ∀ 𝑘 ∈ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ( 𝐼 ‘ ( 𝐹𝑘 ) ) = { ( 𝑃𝑘 ) , ( 𝑃 ‘ ( 𝑘 + 1 ) ) } ) ) )