What is "implicational propositional calculus"

n. (context logic English) A minimalist version of propositional calculus which uses only the logical connectives $to$ ("implies") and $bot$ ("false").

In mathematical logic, the implicational propositional calculus is a version of classical propositional calculus which uses only one connective, called implication or conditional. In formulas, this binary operation is indicated by "implies", "if ..., then ...", "→", " →  ", etc..