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Equation 3 · Part 1 · The Economics and Physical Limits of Running AI Agents at Scale

Symbol delta

δ\delta
δ\delta

What this part means

the call this.

Its job in the formula

delta is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Where the article explains it

Call this δ\delta .

The passage around this formula

The second component is genuinely new content: whatever this step adds that the loop has not seen before — a fresh tool result, a new instruction, an observation from the environment. Call this δ\delta . The third is the step’s own output, call it oˉ\bar{o} , priced at the output rate, which is five times the input rate on every currently supported Claude tier, from Haiku 4.5 through Opus 5, and roughly six times on OpenAI’s GPT-5.6 family [ 1 , 7 ] .

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Learn the underlying idea

A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

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Sources cited in the article section

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