P′′ is a primitive computer programming language created by Corrado Böhm in 1964 to describe a family of Turing machines.
== Definition ==
P
′
′
{\displaystyle {\mathcal {P}}^{\prime \prime }}
(hereafter written P′′) is formally defined as a set of words on the four-instruction alphabet {R, λ, (, )}, as follows:
=== Syntax ===
R and λ are words in P′′.
If p and q are words in P′′, then pq is a word in P′′.
If q is a word in P′′, then (q)...