For "calculus of differences" CSP preferred "calculus of successions." He planned to divide treatise into four parts, but the manuscript only gets into the first part which, treating the subject generally without regard to the na-ture of known quantities, is occupied mainly with equations of differences. The distinction between logical and mathematical functions. Features of mathematical functionality. Definitions of "value," "universe of values." "quantity." Notational rules.
Finite differences calculus of, logical and mathematical Functions, Logic (modal see Modality), Mathematics, Notation (see also Nomenclature Terminology), Quantity, Succession, Universe of values, Value
pp. 1-25, with twice as many pages from other drafts.