Truth table is a propositional formula with n(n 1) propositional variables. * * * Group assignment lists the values of propositional formula A under all assignments, which is called a truth table.

Steps to build a truth table

Find out all the propositional variables contained in the propositional formula (if there is no lower corner, they are given in dictionary order) and list all possible assignments (); Write down all levels in order from low to high; Corresponding to each assignment, the values of all levels of the propositional formula are calculated until the value of the propositional formula is finally calculated.