Roots of Lisp

 This article makes the effort to explain the advance to science that was Lisp in the age that John McCarty wrote it and the main concepts about it, its simplicity but also the smartness of it, considering that in this day and age most programming languages that were based in the formula of c are taking lots of inspiration from Lisps and implementing its functions into their own core it is really worth it to know how the Lisps are made from the inside out.

It comments that everything is either an atom or a list of expressions and an expression yields a return value, it salso talks about the quote that is a way for telling that we do not want  the next list to be evaluated as an expression, because by default every list is an expression the first parameter is going to be considered as a function applied the the next parameters, and if the first parameter is a number or a symbol it will not know what to do with it.

And the most important thing is how we can write functions that can act as interpreters for our language, meaning a function that takes an expression as an argument and returns its value as an output, and this one is called eval, is probably one of the most complex, it takes the expressio to be evaluated and a list of the values of the atom. And after that basically uses simple conditionals to know what kind of expressions we are managing and evaluating the expressions with the values of the atoms and eventually it will return the expected value

All this meaning that with some especial function eval can be defined and with eval being defined we can implement a lot of more function and basically define the language