How deeply does Quantum Programming in Depth cover equality function?

Derives a three-qubit decomposition from XOR and NOT, then validates it through basis-state truth tables.

Equality function

As explained in Quantum Programming in Depth

An equality function outputs one exactly when its two binary inputs are equal.

The equality function returns 1 exactly when two binary inputs are equal. It is the negation of XOR: x₀ EQUAL x₁ = NOT(x₀ XOR x₁). section 6.4.1

Implement the reversible, out-of-place form on three qubits:

Preserve inputs x₀ and x₁ while using y for the output. section 6.4.1
Apply CNOT(x₀, y), then CNOT(x₁, y), producing y ⊕ x₀ ⊕ x₁. section 6.4.1
Apply an in-place NOT to y, converting the XOR result into equality. section 6.4.1
Validate reversible implementations by comparing their basis-state effects with the classical truth table. section 6.4.1

How Quantum Programming in Depth covers it

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Related concepts

signalconfigures · A signal is an observable value, event, or pattern that conveys information about a condition, state, or phenomenon.
reference equalitycontrasts with · Reference equality is equality determined by whether two references designate the same object or instance rather than equivalent values or contents.
logical XORuses · Logical XOR is a binary operation that produces true when exactly one operand is true and false when both operands have the same truth value.

This explainer was generated by Manning's knowledge graph from the text of Quantum Programming in Depth. The section links point to the parts of the book it draws on.