Equation 5 · Part 3 · AI Inference Economics in Practice: An Advanced Technical Guide
Symbol r
What this part means
r is one of the signed contributions combined to compute the quantity on the left.
Its job in the formula
r is one of the signed contributions combined to compute the quantity on the left.
Full expression→Symbol r→Article meaning
The passage around this formula
…roughly one tenth of base input for a cache read — independently verified today across all three platforms [ 2 , 6 , 10 ] — supports a design rule. Let w be the write-price multiplier for the chosen retention window and r 0.1 the read-price multiplier. For a prefix served identically R times within that window — the first serving is the write, the remaining R-1 are reads — caching beats never caching once . is exceeded. At Anthropic’s five-minute rate, w = 1.25 and 1.28 :…
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 surrounding passage
These citations provide research context; check each source for the exact claim it supports.