"One of the most careful and intensive among the introductory texts that can be used with a wide range of students. It builds remarkably sophisticated technical skills, a good sense of the nature of a formal system, and a solid and extensive background for more advanced work in logic. . . . The emphasis throughout is on natural deduction derivations, and the text's deductive systems are its greatest strength. Lemmon's unusual procedure of presenting derivations before … mehrtruth tables is very effective." --Sarah Stebbins, The Journal of Symbolic Logic
https://www.amazon.de/Beginning-Logic-J-Lemmon/dp/0915144506/ref=sr_1_1?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=beginning+logic&qid=1609614136&sr=8-1 weniger