Equation 11 · Part 1 · Claude Code, From First Principles: The Agentic Loop, Permissions, and What Actually Executes
Symbol a_t
What this part means
is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Its job in the formula
is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol a_t→Article meaning
The passage around this formula
The loop repeats until emits a stop rather than a tool call. Nothing in this is exotic; it is the standard shape of a tool-using agent. What matters for this article is what each symbol is standing in for in a real, shipped product: is not a hypothetical action but a call to a real interpreter with real side effects on a real machine, is not simulated feedback but the actual return value of that call, and the boundary between “the model decided” and “the harness allowed” is enforced by software, not by the model’s own restraint.
Learn the underlying idea
A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
Open the illustrated subscripts: which member of a family? guide →
See this notation across published equations →
Sources cited in the article section
- [2] How Claude Code works ↗
- [11] Dive into Claude Code: The Design Space of Today's and Future AI Agent Systems ↗
These citations provide research context; check each source for the exact claim it supports.