| 708 / | HD | ELECTRICAL COMPUTERS: ARITHMETIC PROCESSING AND CALCULATING |
| 800 | DF | ELECTRICAL ANALOG CALCULATING COMPUTER {1} |
| 801 | DF | .~ Particular function performed {15} |
| 802 | DF | .~.~ Evaluation of equation {2} |
| 804 | ![]() | .~.~.~ Differential (e.g., differential analyzer) |