Sources spreadsheets saw in 1961 the concept of an electronic spreadsheet in Article Budgeting Models and System Simulation by Richard Mattessich. Pardo and Landau deserve some cr for such programs, and actually tried to patent (U.S. patent number 4,398,249) some of the algorithms in 1970. The patent was not granted by the patent office for being a purely mathematical invention. Pardo and Landau won a court case stating that “something no longer be patentable merely because the point of novelty is an algorithm. This case helped start of software patents. Dan Bricklin is the generally accepted inventor of the spreadsheet. Bricklin told the story of a college professor who made a table of calculations on a board.When the professor found an error, had to erase and rewrite a lot of very tedious steps, triggering Bricklin to think that could replicate the process on a computer, using the paradigm board / spreadsheet to see the results of the formulas involved in the process. His idea became VisiCalc, the first spreadsheet, and “critical application” that made the PC (personal computer or computer) would no longer be just a hobby for computer enthusiasts to become also a tool in business and in companies.