TY  - BOOK
AU  - Velleman, Daniel J. 
TI  - How to prove it : : a structured approach 
SN  - 9781108439534     Pbk. 
AV  - QA 9 V45 2019 CIRC 
PY  - 2019///.
CY  - New York, NY
PB  - Cambridge University Press, 
KW  - Logic, Symbolic and mathematical--Textbooks
KW  - Mathematics--Textbooks
KW  - Proof theory--Textbooks
N1  - Includes bibliographical references and index.
ER  -