From time to time, I receive requests from mathematicians for recommendations on scientific literature. My recommendation is always chapter 5 of Andrews’ 2002 textbook, in which the higher-order logic Q0 is presented [Andrews, 2002, pp. 210–215], and elementary logic developed (e.g., the derivation of the rule of Modus Ponens [p. 224]). For the full reference, please see the overview.

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