In 1847 Berti wrote a book named " Samouka pokus pervi " in which he offered a rudimentary algebraic language of thoughts and concepts ( including variables, constants, equality sign ) to which the law of substitution is added, which was the beginning stage of Boolean logic.
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A well-known example was the development of analytic geometry, which in the hands of mathematicians such as Descartes and Fermat showed that many theorems about curves and surfaces of special types could be stated in algebraic language ( then new ), each of which could then be proved using the same techniques.
