Read the equation
Sums −p log p over the stated probability distribution. Valid probabilities must be nonnegative and sum to one; the logarithm base fixes the units, and the conventional zero-probability contribution is zero.
Terms & definitions
The recovered passage does not supply a separate symbol table. Read the source context for the notation used in this version; familiar letters may carry different meanings in other builds.
How it works
Read S as the quantity being defined or updated by this relation.
Adds the indexed contributions. The summation limits determine which components participate.
Uses logarithmic scaling; its base and the positivity of its argument matter.
Use this version’s variable definitions and update order. The same symbol may be assigned a different meaning in another build.
Assumptions & limits
Source recovery establishes that the expression appears in this record. Its mathematical validity, implementation behavior, and interpretation must be assessed separately. See the linked source and research notes for the checks available for this version.
Original context
Read the surrounding source passage
D. Entropy Term You talked about compression but never added the math: S = -\sum p_i \log p_i Needed to formalize the binary shrink process (Rbin). ⸻ E. Error Propagation Operator
Exact original notation
S = -\sum p_i \log p_i