The paper concludes that a "remarkably elegant model of computation" can be made using just 7 primitive operators, which allows for defining a self-interpreter.

The paper concludes that a "remarkably elegant model of computation" can be made using just 7 primitive operators, which allows for defining a self-interpreter. In fact, 0 primitive operators suffice, as the ability to denote functions (Section 2) gives us the Turing complete lambda calculus. A self-interpreter for a version of lambda calculus denoted in binary fits in under 26 bytes, as shown on http://www.cwi.nl/~tromp/cl/cl.html http://www.cwi.nl/~tromp/cl/cl.html