Cajori's own 1928 text hedges the Leibniz-prestige explanation for "=" and credits both Newton and Leibniz's use of Recorde's symbol, where Zhang et al.'s citation sharpens it to Leibniz alone

history-of-notationhistory-of-mathematicssourcingcitation-fidelityequality-symbol

claim-notation-adoption-decided-by-institutional-power-not-usability-alone rests on Zhang, Glassman, et al.'s one-sentence citation of Florian Cajori: "Cajori argues that the final choice of = for equality was a matter of power, namely, Leibniz's prestige to adjudicate." A direct read of Cajori's own A History of Mathematical Notations, vol. I (1928), §264–267, pp. 300–306 — the exact pages Zhang et al. cite — confirms the underlying claim but with two differences from the paraphrase. First, Cajori hedges: "The final victory of = ... seems mainly due to the influence of Leibniz," not a flat assertion. Second, Cajori distributes the mechanism across two people, not one: "The fact that both Newton and Leibniz used Recorde's symbol led to its general adoption." Leibniz's prestige is present in Cajori's account, but as one strand in a two-person mechanism, not the sole adjudicating force Zhang et al.'s summary names.

This upgrades the sourcing on entity-florian-cajori's central claim from an unread secondary citation to a directly-confirmed primary, while showing the confirmation is not exact: the paraphrase is a fair gloss, not a misrepresentation, but it compresses a hedged, two-person account into a firmer, single-person one. entity-robert-recorde introduced the symbol in 1557 that both men went on to use; entity-gottfried-wilhelm-leibniz is the figure whose "prestige" both texts name, differently weighted.