Count the number of variables in the expression. For n Boolean variables will need 2^n rows in the table the truth, not counting lines with headers. Then count the number of logical operations in the expression. Columns in the table will be the same as the operations plus n columns for variables.
Let this expression with three variables recorded in figure. Three variables, so strings will need 8. The number of operations is 3, so the number of columns variable is equal to 6. Draw a table and fill in its title.
How to build <strong>table</strong> <b>truth</b>
Now fill in the columns labeled with names of variables, all possible variables. So as not to miss one variant, it is convenient to represent these sequences of zeros and ones as binary numbers from 0 to 2^n. For the three variables is a binary number from 0 to 8, or from 000 to 111 in binary notation.
How to build <strong>table</strong> <b>truth</b>
Start to fill the table of truth the most suitable document the results of the denial of the variables, since there is no need to do any complex reasoning. In our case, it is easy to fill in the column of the negation of the variable B.
How to build <strong>table</strong> <b>truth</b>
Then substitute successively the values of the variables in the Boolean operations indicated in the column headings, and record in the appropriate cells of the table, sequentially filling the table.
How to build <strong>table</strong> <b>truth</b>