A·B + C·D — truth table
exam standard16 rows, 7 true
Answer
16 rows, 7 true (3, 7, 11, 12, 13, 14, 15)
Why this example is worth doing
Four variables, sixteen rows, and the first table that will not fit on a phone screen. It is here to demonstrate the mobile behaviour promised in the spec: the table scrolls horizontally inside its own container with the variable columns pinned, while the page itself never scrolls sideways. It is also the canonical two-level AND-OR structure, so the converter bar leads directly to a gate diagram of exactly two AND gates feeding one OR gate.
Try your own input in the Truth table generator. Turn an expression into a full truth table, with a column for every sub-expression.
How the answer is reached
Truth table
| # | A | B | C | D | A · B + C · D |
|---|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | 0 | 0 | 0 | 1 | 0 |
| 2 | 0 | 0 | 1 | 0 | 0 |
| 3 | 0 | 0 | 1 | 1 | 1 |
| 4 | 0 | 1 | 0 | 0 | 0 |
| 5 | 0 | 1 | 0 | 1 | 0 |
| 6 | 0 | 1 | 1 | 0 | 0 |
| 7 | 0 | 1 | 1 | 1 | 1 |
| 8 | 1 | 0 | 0 | 0 | 0 |
| 9 | 1 | 0 | 0 | 1 | 0 |
| 10 | 1 | 0 | 1 | 0 | 0 |
| 11 | 1 | 0 | 1 | 1 | 1 |
| 12 | 1 | 1 | 0 | 0 | 1 |
| 13 | 1 | 1 | 0 | 1 | 1 |
| 14 | 1 | 1 | 1 | 0 | 1 |
| 15 | 1 | 1 | 1 | 1 | 1 |