Text next double character- Tf

- Instruction: Tf - Parameter: none - Return: true if the next two characters are equal - Description: Returns true if the next two characters after the index are equal, that is, they are doubles. For example, if there is a pair "bb" after the index, the instruction returns true. This instruction does not want any other parameters, since the doubles detected can be of any character. - Examples: Text string: a Braille string: 456 Condition: Tf Description: The character "a" is transcribed with the cell "456" if it is followed by a pair of equal characters, such as "bb", "ll", "55" etc..