**P′′** (P double prime^{[1]}) is a primitive computer programming language created by Corrado Böhm^{[2][3]} in 1964 to describe a family of Turing machines.

Definition

P (hereinafter written **P′′**) is formally defined as a set of words on the four-instruction alphabet.

Relation to other programming languages

- P′′ was the first “GOTO-less” imperative structured programming language to be proven Turing-complete
^{[2][3]} - The Brainfuck language (apart from its I/O commands) is a minor informal variation of P′′. Böhm gives explicit P′′ programs for each of a set of basic functions sufficient to compute any computable function, using only {\textstyle (}, {\textstyle )}and the four Example program[edit]

Böhm^{[2]} gives the following program to compute the predecessor (*x*-1) of an integer *x* > 0:

which translates directly to the equivalent Brainfuck program:

* *>**[**>**]**<**[***−***[**<**[**<**]]***−*<**]**>+

The program expects an integer to be represented in *bijective base-k* notation.

References

**^**https://github.com/Pbtflakes/pdbl- ^ Jump up to:
^{a}^{b}Böhm, C.: “On a family of Turing machines and the related programming language”, ICC Bull. 3, 185-194, July 1964.^{c} - ^ Jump up to:
^{a}Böhm, C. and Jacopini, G.: “Flow diagrams, Turing machines and languages with only two formation rules”, CACM 9(5), 1966. (Note: This is the most-cited paper on the structured program theorem.)^{b}