TY  - BOOK
AU  - Velleman, Daniel J
TI  - How to prove it : a structured approach 
SN  - 9781108439534
AV  - QA 9 Vel 
PY  - 2019///
CY  - Cambridge
PB  - Cambridge University Press
KW  - PROOF THEORY
KW  - LOGIC, SYMBOLIC AND MATHEMATICAL
KW  - MATHEMATICS
ER  -