| 摘要 |
PROBLEM TO BE SOLVED: To enable calculation which varies the value of a variable by registering variables by time and calculating the future value of the variable by a program. SOLUTION: An output part 7 directly accesses a storage part 1 for variable history to reads out the current value of the variable, and output it to outside the system, e.g. a display 3 on the basis of the value. Through the execution of an input part 8 and user programs 61 -6n controlling input from a mouse 4, a keyboard 5, etc., to the system, the variable is read out and updated through a time management part 2. The time management part 2 holds a time variable, and then performs management so that when the variable is read out, the value before the time of the time variable can not be read out and also adds and records the time of the time variable at the same time when the variable is varied. Thus, the history of the variable is stored and a new variable value is calculated according to the description declaring the relation between the past state and future state, and the progress of the calculation by declarative description is so controlled as the synchronize with the time of a actual clock. |
