The seven source turns contain assigned counts totaling five hundred ten, under the assigned five hundred twelve token window. Bars use one pixel per assigned token. The FIFO branch nevertheless explicitly marks turn one evicted and assigns thirty-six evicted tokens; this is not a budget-driven packing algorithm. The example illustrates a possible lost constraint, not observed ChatGPT behavior, tokenization or a real response. The pinning branch labels the first constraint as a system pin and marks the two hundred forty token fourth turn evicted. It assigns used tokens two hundred seventy versus FIFO four hundred seventy-four. Bars use one pixel per assigned token. These totals are branch fixtures; they should not be taken as a measured tokenizer accounting or proof that any real product always preserves instructions. No model call runs. The summary branch replaces the first four source turns with a forty token summary record. Those original turn counts total two hundred eighty-one. Bars show two hundred eighty-one original assigned tokens versus forty summary tokens, at one point seven pixels per token. The record is written in the source, not generated by a background model. Its fixed remembered label illustrates preservation of a constraint, not semantic fidelity or factual correctness of arbitrary summarization.