Equation 46 · Part 2 · The Entry a Relabeling Cannot Write

Symbol H_f

D_\Lambda = H_f - H_f = 0

H_f

What this part means

$H_f$ is one of the signed contributions combined to compute the quantity on the left.

Its job in the formula

$H_f$ is one of the signed contributions combined to compute the quantity on the left.

Full expressionSymbol H_fArticle meaning

The passage around this formula

using only $W^\dagger$ W = I . So $D_\Lambda$ = $H_f$ - $H_f$ = 0 , identically, as an operator, for every unitary W and every $H_f$ . This is not a limit, an approximation, or a property of some special state; it is an algebraic identity that holds before any state is chosen at all.

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

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See this notation across published equations →

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