How to simplify LISP?

Question

Lisp

For academic purposes, I want to use the task of writing a LISP interpreter. A fairly common practice. However, LISP is still too complicated for my purposes, so I want to simplify it. And since I am not a professional of this language, I decided to consult if I would throw out something necessary.
So, I want to do the following:
1) from atoms, leave only integer decimal numbers and identifiers (consisting of letters and an underscore);
2) remove dotted pairs altogether (they can be replaced by lists of two elements);
3) leave only these functions: cons, car, cdr, if, defun, quote and even arithmetic ones.
Will this language remain Turing complete? Did I throw out something necessary? Or vice versa, maybe left something redundant?
My goal is to keep the spirit of LISP while keeping the syntax as short as possible.

Answer 1

What is the "minimal" set of primitives needed for...
The Lisp defined in McCarthy's 1960 paper, transla...

Answer 2

(cons 1 2) => '(1 . 2)
And a two-element list is (cons 1 (cons 2 nil))
So I'm afraid you can't do without dotted pairs. They are not related specifically to "pairs of elements", but to the construction of list cells. Try (cons 1 (cons 2 3)) and see.
By the way, you will also need the mentioned nil (and, accordingly, T).
Comparison is required. I do not exclude that you added it to the arithmetic functions, but the comparison of logical values ​​​​is also an absolutely necessary thing.
And finally, you need the ability to distinguish a list from an atom. As far as I remember, atomp or consp is necessarily included in the Lisp core. This does not seem to affect Turing completeness, but it will not work to implement it outside the kernel, as a function using primitives.

Answer 3

Look at the Clojure implementation

Answer 4

According to Turing, Lisp will remain complete even if one lambda is left in it.
And Lisp itself is a very simple language. If you don't want to implement all sorts of floating points and strings on your own, write an interpreter in Lisp itself.

Answer 5

mr.gy/software/microlisp
Zs I myself am still a complete teapot in l / hypo-like languages, so I don’t know how much this dialect that I gave the link fits the task) but since it’s micro, it means that the most necessary current is left there - in theory)

Answer 6

Don't forget to remove the brackets.