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Equation 1 · Part 9 · Reactor Phylogenetics: The Family Tree of Fission Power

addition

P(next adopter=A∣nA,nB)=nA+anA+nB+a+bP(\text{next adopter} = A \mid n_A, n_B) = \frac{n_A + a}{n_A + n_B + a + b}
addition

What this part means

Add the term after the plus sign to the term or group before it.

Its job in the formula

Add the term after the plus sign to the term or group before it.

The passage around this formula

Graded against biological evolution, several parts of this history are exact rather than merely suggestive. Descent is literal: design documents, safety-case arguments, and component specifications pass from Nautilus to Shippingport to the commercial PWR fleet as physical inheritance, not metaphorical resemblance. Variation across national programs — American, French, Soviet, British, Canadian, Chinese — produced genuinely distinct lineages under geographic and institutional isolation, exactly as allopatric speciation produces distinct populations under geographic separation. Selection by markets, regulators, and accidents is observably real and, in the case of TMI, Chernobyl, and Fukushima,…

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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.

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Sources cited in the surrounding passage

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