*What is Calculus?*

**• The method "Executable Pictograms" basically is the content of a ****calculus****, in its most general sense **

**(****different from that in mathematics:**** Non-standard calculus [Infinitesimal Calculus {hyperreal numbers}], Standard calculus [Fundamental theorem of calculus ****<https://en.wikipedia.org/wiki/Fundamental_theorem_of_calculus>**** {differential calculus ****<https://en.wikipedia.org/wiki/Differential_calculus>****, integral calculus}], Calculi [Computer Science, Software Engineering])**

**, for programming.**

**• ****More generally, calculus (plural calculi)**** refers to any method or system of calculation guided by the**** symbolic manipulation of expressions****.**