This function will print the questions in the interactive learning environment.
sessionQuestions(assign.env = parent.frame(1))
https://www.supermemo.com/english/ol/sm2.htm SuperMemo-2 algorithm
This function reads the selected dataset and print the first row of its first colomn, i.e. the question. Then it presents to the user a menu, which gives him multiple choices. According to the choice made by the user, the function gives a score point and will return a due date, inspired by the SuperMemo-2 and Anki algorithms. The menu also proposes to show the answer (the 2nd column of the row), to give a hint/example, or to go back to the main menu. Finally, the function reorders the dataset in order to get the lower points score in its first row and return the function once again.
In order to quit, simply type 0.