phase-visibility-minimum-three-row-scan - Quantum Measurement and Coherence Windows Step by Step

The coherent fraction can pass, meet, or fail a visible-count floor. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Visibility is an ideal count scaled by coherent fraction

The ideal count is fixed while the coherent share changes across the rows.

N_{\text{visible}}=N_{\text{ideal}}f_{\text{coh}}

Three coherent shares bracket the minimum visible signal

The boundary row is accepted by equality; the final row is below the minimum.

\begin{array}{c|c|c|c}N_{\text{coh}}&f_{\text{coh}}&N_{\text{vis}}&m\\80&1&40&15\\50&\frac{5}{8}&25&0\\20&\frac{1}{4}&10&-15\\\end{array}

The low-coherence row fails the visible-count minimum

The phase-visibility helper computes the smaller count; the lesson gate only compares it with the minimum.

m=-15\quad \text{fail}