Abstract: There is provided with a device that includes a first inputter inputting design description which includes functions; a second inputter inputting type specifying description corresponding to the functions, each of which specifies a type for a return value of each corresponding function, and the description of at least one function of the functions specifies a type for a return value of a first function which is an other function of functions; a determiner determining a type of the return value of the first function to a comprehensive type to comprehend the types specified by the type specifying description corresponding to the first function and the at least one function and a type of the return value of a second function which is a function than the first function to the type specified thereto.

Abstract: A variable is allocated to a statement that designates an event associated with a function call in an assertion. Generation of the event at an arbitrary time on a continuous time series is detected, and a value corresponding to a meaning of the statement is assigned to the variable. Whether or not a condition corresponding to the meaning of the statement is satisfied is determined based on the value of the variable at each time on a discrete time series.

Abstract: A design automaton extractor extracts a design automaton from design description data, and a property automaton extractor extracts a property automaton from property description data corresponding to the design description data. A matched state detector counts all states of the design automaton, detects matched states matching the property automaton from all the states of the design automaton, and counts the matched states. A coverage calculator obtains a ratio of the number of matched states to the number of all the states of the design automaton, thereby calculating a coverage representing the degree of correspondence of the property description data to the design description data.