au=bernauthor basedon=3.3 Section Exercise 15 bau=Bello bname=Topics in Contemporary Mathematics by Bello 2008, ed. 9, ISBN 0618775242 book=usf_math_bello_tcm_9e btitle=Topics in Contemporary Mathematics chap=3 cname=Logic comm=p15 difflev=0 edt=9 error= extlink= gradable=1 ilev=1 isbn=0618775242 kw= lo=3.3.1 loname=The Biconditional page= parse=preview pr=bernproofer pt=full sect=3 sname=The Conditional and the Biconditional source= spell=preview st=gold taxon= tname=table view=edit_h warn=0 year=2008