Abstract: Provided is a computer system including an information providing server and a computer which is coupled to the information providing server, and which collects information, the computer being configured to: record status histories including a history of an operation to a screen which shows a status of the computer, and which is displayed on the computer in chronological order to constitute a set of the status histories; and divide, in a case where a history of an operation of switching the screen is detected from the set of the status histories, based on the history of the operation of switching the screen, the set of the status histories. Accordingly, when a user collects information, navigation information is provided by taking the fact that the user has actually reached useful information into consideration.

Abstract: Provided is a computer system including an information providing server and a computer which is coupled to the information providing server, and which collects information, the computer being configured to: record status histories including a history of an operation to a screen which shows a status of the computer, and which is displayed on the computer in chronological order to constitute a set of the status histories; and divide, in a case where a history of an operation of switching the screen is detected from the set of the status histories, based on the history of the operation of switching the screen, the set of the status histories. Accordingly, when a user collects information, navigation information is provided by taking the fact that the user has actually reached useful information into consideration.

Abstract: The present invention relates to novel pharmaceutical use of forskolin derivatives represented by the general formula: ##STR1## wherein R.sup.1, R.sup.2 and Ac are as defined later ##STR2## (wherein R.sup.3 and R.sup.4 are each hydrogen or lower alkyl group, or R.sup.3 and R.sup.4 may be combined to represent lower alkylene group which may have oxygen or nitrogen atom in the linking chain, and n is an integer of 1 to 5); R.sup.2 represents hydrocarbon group having 2 to 3 carbon atoms; and Ac represents acetyl group.The above-mentioned forskolin derivative or a physiologically acceptable salt thereof can be used as a platelet aggregation inhibiting or controlling agent, spasmolytic agent, therapeutic agent for skin ulcer, peripheral circulation improving agent for limbs and differentiation inducing and promoting agent.