Punctuation centuries meant that a standard system of punctuation was urgently required." The introduction of a standard system of punctuation has also been attributed to the Venetian printers Aldus Manutius and his grandson. They have been credited with popularizing the practice of ending sentences with the colon or full stop, inventing the semicolon, making occasional use of parentheses and creating the modern comma by lowering the virgule. By 1566, Aldus Manutius the Younger was able to state that the main object of punctuation was the clarification of syntax. By the 19th century, punctuation in the western world had evolved "to classify
That that is is that that is not is not is that it it is was noted in "Brewer's Dictionary of Phrase and Fable". This phrase appeared in the 1968 American movie "Charly", written to demonstrate punctuation to the main character Charly's teacher, in a scene to demonstrate that the surgical operation to make the character smarter had succeeded. That that is is that that is not is not is that it it is That that is is that that is not is not is that it it is is an English word sequence demonstrating syntactic ambiguity. It is used as an example illustrating the importance of proper punctuation. The sequence can be understood as