Metamath Proof Explorer


Theorem pmtrfval

Description: The function generating transpositions on a set. (Contributed by Stefan O'Rear, 16-Aug-2015)

Ref Expression
Hypothesis pmtrfval.t T = pmTrsp D
Assertion pmtrfval D V T = p y 𝒫 D | y 2 𝑜 z D if z p p z z

Proof

Step Hyp Ref Expression
1 pmtrfval.t T = pmTrsp D
2 elex D V D V
3 pweq d = D 𝒫 d = 𝒫 D
4 3 rabeqdv d = D y 𝒫 d | y 2 𝑜 = y 𝒫 D | y 2 𝑜
5 mpteq1 d = D z d if z p p z z = z D if z p p z z
6 4 5 mpteq12dv d = D p y 𝒫 d | y 2 𝑜 z d if z p p z z = p y 𝒫 D | y 2 𝑜 z D if z p p z z
7 df-pmtr pmTrsp = d V p y 𝒫 d | y 2 𝑜 z d if z p p z z
8 vpwex 𝒫 d V
9 8 mptrabex p y 𝒫 d | y 2 𝑜 z d if z p p z z V
10 6 7 9 fvmpt3i D V pmTrsp D = p y 𝒫 D | y 2 𝑜 z D if z p p z z
11 2 10 syl D V pmTrsp D = p y 𝒫 D | y 2 𝑜 z D if z p p z z
12 1 11 eqtrid D V T = p y 𝒫 D | y 2 𝑜 z D if z p p z z