A toy quantum table separates constant from balanced functions. This is a toy exact table; real quantum algorithms also use complex amplitudes and interference. The one-query test decides constant versus balanced; it does not read both function values.

Example

A toy quantum table separates constant from balanced functions. This is a toy exact table; real quantum algorithms also use complex amplitudes and interference. The one-query test decides constant versus balanced; it does not read both function values.

highlighted = computed this step

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\hlmath{\text{after query pair=(0,0)}}\end{array}

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\hlmath{\text{final measure=0}}\end{array}

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0f(0)=1 f(1)=1after query pair=(1,1)\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\text{final measure=0}\\\text{f(0)=1 f(1)=1}&\hlmath{\text{after query pair=(1,1)}}\end{array}

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0f(0)=1 f(1)=1after query pair=(1,1)constant onefinal measure=0\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\text{final measure=0}\\\text{f(0)=1 f(1)=1}&\text{after query pair=(1,1)}\\\text{constant one}&\hlmath{\text{final measure=0}}\end{array}

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0f(0)=1 f(1)=1after query pair=(1,1)constant onefinal measure=0f(0)=0 f(1)=1after query pair=(0,1)\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\text{final measure=0}\\\text{f(0)=1 f(1)=1}&\text{after query pair=(1,1)}\\\text{constant one}&\text{final measure=0}\\\text{f(0)=0 f(1)=1}&\hlmath{\text{after query pair=(0,1)}}\end{array}

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0f(0)=1 f(1)=1after query pair=(1,1)constant onefinal measure=0f(0)=0 f(1)=1after query pair=(0,1)balanced identityfinal measure=1\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\text{final measure=0}\\\text{f(0)=1 f(1)=1}&\text{after query pair=(1,1)}\\\text{constant one}&\text{final measure=0}\\\text{f(0)=0 f(1)=1}&\text{after query pair=(0,1)}\\\text{balanced identity}&\hlmath{\text{final measure=1}}\end{array}

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0f(0)=1 f(1)=1after query pair=(1,1)constant onefinal measure=0f(0)=0 f(1)=1after query pair=(0,1)balanced identityfinal measure=1f(0)=1 f(1)=0after query pair=(1,0)\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\text{final measure=0}\\\text{f(0)=1 f(1)=1}&\text{after query pair=(1,1)}\\\text{constant one}&\text{final measure=0}\\\text{f(0)=0 f(1)=1}&\text{after query pair=(0,1)}\\\text{balanced identity}&\text{final measure=1}\\\text{f(0)=1 f(1)=0}&\hlmath{\text{after query pair=(1,0)}}\end{array}

Build the concrete table

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0f(0)=1 f(1)=1after query pair=(1,1)constant onefinal measure=0f(0)=0 f(1)=1after query pair=(0,1)balanced identityfinal measure=1f(0)=1 f(1)=0after query pair=(1,0)balanced notfinal measure=1\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\text{final measure=0}\\\text{f(0)=1 f(1)=1}&\text{after query pair=(1,1)}\\\text{constant one}&\text{final measure=0}\\\text{f(0)=0 f(1)=1}&\text{after query pair=(0,1)}\\\text{balanced identity}&\text{final measure=1}\\\text{f(0)=1 f(1)=0}&\text{after query pair=(1,0)}\\\text{balanced not}&\hlmath{\text{final measure=1}}\end{array}

Read the table verdict

Compute the highlighted logic-table value.

f(0)=0 f(1)=0after query pair=(0,0)constant zerofinal measure=0f(0)=1 f(1)=1after query pair=(1,1)constant onefinal measure=0f(0)=0 f(1)=1after query pair=(0,1)balanced identityfinal measure=1f(0)=1 f(1)=0after query pair=(1,0)balanced notfinal measure=1verdictinterference: measure 0 means constant, 1 means balanced\begin{array}{c|c}\text{f(0)=0 f(1)=0}&\text{after query pair=(0,0)}\\\text{constant zero}&\text{final measure=0}\\\text{f(0)=1 f(1)=1}&\text{after query pair=(1,1)}\\\text{constant one}&\text{final measure=0}\\\text{f(0)=0 f(1)=1}&\text{after query pair=(0,1)}\\\text{balanced identity}&\text{final measure=1}\\\text{f(0)=1 f(1)=0}&\text{after query pair=(1,0)}\\\text{balanced not}&\text{final measure=1}\\\text{verdict}&\hlmath{\text{interference: measure 0 means constant, 1 means balanced}}\end{array}
logic-computation Every row is intentionally ordered and pinned to the lesson specification.