← Back to article

Equation 6 · Claude Code, From First Principles: The Agentic Loop, Permissions, and What Actually Executes

What does this equation mean?

at=π(ct).a_t = \pi(c_t).

Read the formula alongside the article passage below. Each part has a deeper page with its role in the equation, the supporting passage and nearby citations.

Inputs and operationspi(c_t)
Result or conditiona_t
How to read the two sides of this formula. Follow the article passage for the meaning of each quantity.

This equation states an equality: the expressions on both sides have the same value under the article’s assumptions. Read the equation part by part below; each part has a contextual explanation and a link to its mathematical background.

Read it piece by piece

ata_t

Symbol a_t

ata_t is part of the quantity the equation computes from the expression on the right.

Understand this part →

π\pi

Symbol pi

pi is an input to the expression that computes the quantity on the left.

Understand this part →

ctc_t

Symbol c_t

ctc_t is an input to the expression that computes the quantity on the left.

Understand this part →

=

=

The expressions on both sides represent the same quantity under the stated assumptions.

Understand this part →

See an illustrated explanation →
subscript

subscript

The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.

Understand this part →

How to interpret it

Read it with the definitions, units, and assumptions supplied by the article.

What the article says around this equation

Let ctc_t be the context available to the model at step t : system instructions, conversation so far, file contents, tool outputs. The model is a policy π\pi that, given ctc_t , emits either a final answer or a tool call ata_t : at=π(ct)a_t = \pi(c_t). Claude Code executes ata_t — subject to a permission check described in the next section — against the real filesystem, shell, or network, producing an observation oto_t : a diff applied, a command’s stdout and exit code, a search result. That observation is appended to the context for the next step:

Read the equation in its article →

Sources cited in the article section

These citations give research context. Read each source to check which claims it supports.

Return to Claude Code, From First Principles: The Agentic Loop, Permissions, and What Actually Executes

See this formula across 1 published context →

Browse the mathematical compendium →