← All parts of this equation

Equation 12 · Part 4 · How Fast Can a Horizon Learn Which Path You Took?

subtraction

h2(p)=−plog⁡2p−(1−p)log⁡2(1−p)h_2(p)=-p\log_2p-(1-p)\log_2(1-p)
subtraction

What this part means

Subtract the following term or group from the preceding one. A leading minus marks a negative quantity.

Its job in the formula

Subtract the following term or group from the preceding one. A leading minus marks a negative quantity.

The passage around this formula

where h2(p)=−plog⁡2p−(1−p)log⁡2(1−p)h_2(p)=-p\log_2p-(1-p)\log_2(1-p). is binary entropy. The first equation inherits quantum minimum-error detection [ 14 ] . The second is ordinary mutual information for the resulting binary channel. It answers a concrete question: if one path bit was chosen fairly and one optimized single-shot yes/no measurement was made, how many bits did that decision convey on average?

Read this part in the article →

Learn the underlying idea

Addition combines quantities; subtraction measures the signed difference between them. Parentheses show what is combined before the rest of the expression is evaluated.

Open the illustrated addition and subtraction in an equation guide →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.