
The main output is outputb it lights down right corner if the input combination is correct
Try different combinations if it is correct outputb lights together with the line on oppositing site.
Your hand (and I find numpad useful.)
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | inputa | outputa | |
| 1 | inputb | ||
| 2 | inputc | outputb | |
| 3 | inputd | ||
| 4 | inputd | outputc | |
| 5 | inpute | ||
| 6 | inputf | ||
| 7 | inputg | outputd |