P′′ (English Wikipedia)

Analysis of information sources in references of the Wikipedia article "P′′" in English language version.

Last modified: 11:29:56, 16 August 2026 (UTC)

Ref.Un. Ref.Website

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127cambridge.org

209^th place

151^st place

75doi.org

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75semanticscholar.org

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11esolangs.org

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11github.com

380^th place

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cambridge.org (Global: 209^th place; English: 151^st place)

Böhm defines a unary predicate — $p$ in Böhm (1964, p. 187), $\alpha$ in Böhm & Jacopini (1966, p. 370) — that is true iff the square actually scanned (by the Turing machine head) is blank (i.e. contains $\Box$ ). Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194. Böhm, Corrado; Jacopini, Giuseppe [in Italian] (May 1966). "Flow Diagrams, Turing Machines and Languages with Only Two Formation Rules". Communications of the ACM. 9 (5): 366–371. doi:10.1145/355592.365646. S2CID 10236439. Republished in Yourdon 1979, pp. 13–25
In the context of P′′, repetition could equivalently be written using bracket notation $[\,\cdot \,]^{k}$ , as in Böhm (1964). However, since square brackets already denote the repetition (loop) operator in Brainfuck, we instead use braces $\{\,\cdot \,\}^{k}$ to indicate repetition of an instruction sequence and avoid notational ambiguity. Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194.
Böhm 1964. Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194.
Böhm 1964, p. 185. Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194.
Böhm 1964, pp. 190, 190, 187 (footnote). Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194.
Böhm 1964, p. 191, Main result of this paper. Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194.
Böhm 1964, p. 189. Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194.

doi.org (Global: 2^nd place; English: 2^nd place)

Böhm defines a unary predicate — $p$ in Böhm (1964, p. 187), $\alpha$ in Böhm & Jacopini (1966, p. 370) — that is true iff the square actually scanned (by the Turing machine head) is blank (i.e. contains $\Box$ ). Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194. Böhm, Corrado; Jacopini, Giuseppe [in Italian] (May 1966). "Flow Diagrams, Turing Machines and Languages with Only Two Formation Rules". Communications of the ACM. 9 (5): 366–371. doi:10.1145/355592.365646. S2CID 10236439. Republished in Yourdon 1979, pp. 13–25
Dijkstra (1968): "The unbridled use of the go to statement has as an immediate consequence that it becomes terribly hard to find a meaningful set of coordinates in which to describe the process progress. ... The go to statement as it stands is just too primitive, it is too much an invitation to make a mess of one's program." Dijkstra, Edsger (March 1968). "Go To Statement Considered Harmful". Communications of the ACM. 11 (3): 147–148. doi:10.1145/362929.362947. S2CID 17469809.
Böhm & Jacopini 1966. Böhm, Corrado; Jacopini, Giuseppe [in Italian] (May 1966). "Flow Diagrams, Turing Machines and Languages with Only Two Formation Rules". Communications of the ACM. 9 (5): 366–371. doi:10.1145/355592.365646. S2CID 10236439. Republished in Yourdon 1979, pp. 13–25
Böhm & Jacopini 1966, p. 370. Böhm, Corrado; Jacopini, Giuseppe [in Italian] (May 1966). "Flow Diagrams, Turing Machines and Languages with Only Two Formation Rules". Communications of the ACM. 9 (5): 366–371. doi:10.1145/355592.365646. S2CID 10236439. Republished in Yourdon 1979, pp. 13–25
Dijkstra 1968. Dijkstra, Edsger (March 1968). "Go To Statement Considered Harmful". Communications of the ACM. 11 (3): 147–148. doi:10.1145/362929.362947. S2CID 17469809.

esolangs.org (Global: low place; English: low place)

Esolang (2026): "In publishing the formal programming language P′′ in 1964, Corrado Böhm used six symbols precisely equivalent to the brainfuck commands +, -, <, >, [, and ], and provided an explicit program for each of the basic functions that together serve to compute any partial recursive function. (So in a very real sense, the first "brainfuck" programs appear in Bohm's 1964 paper.)" Esolang, Wiki (2026). "Brainfuck". Esolang. Retrieved 13 February 2026.

github.com (Global: 380^th place; English: 337^th place)

GitHub 2021. GitHub (4 September 2021). "PDBL: A tool for Turing machine simulation". GitHub.

semanticscholar.org (Global: 15^th place; English: 8^th place)

api.semanticscholar.org

Böhm defines a unary predicate — $p$ in Böhm (1964, p. 187), $\alpha$ in Böhm & Jacopini (1966, p. 370) — that is true iff the square actually scanned (by the Turing machine head) is blank (i.e. contains $\Box$ ). Böhm, Corrado (1964). "On a family of Turing machines and the related programming language" (PDF). ICC Bulletin. 3: 185–194. Böhm, Corrado; Jacopini, Giuseppe [in Italian] (May 1966). "Flow Diagrams, Turing Machines and Languages with Only Two Formation Rules". Communications of the ACM. 9 (5): 366–371. doi:10.1145/355592.365646. S2CID 10236439. Republished in Yourdon 1979, pp. 13–25
Dijkstra (1968): "The unbridled use of the go to statement has as an immediate consequence that it becomes terribly hard to find a meaningful set of coordinates in which to describe the process progress. ... The go to statement as it stands is just too primitive, it is too much an invitation to make a mess of one's program." Dijkstra, Edsger (March 1968). "Go To Statement Considered Harmful". Communications of the ACM. 11 (3): 147–148. doi:10.1145/362929.362947. S2CID 17469809.
Böhm & Jacopini 1966. Böhm, Corrado; Jacopini, Giuseppe [in Italian] (May 1966). "Flow Diagrams, Turing Machines and Languages with Only Two Formation Rules". Communications of the ACM. 9 (5): 366–371. doi:10.1145/355592.365646. S2CID 10236439. Republished in Yourdon 1979, pp. 13–25
Böhm & Jacopini 1966, p. 370. Böhm, Corrado; Jacopini, Giuseppe [in Italian] (May 1966). "Flow Diagrams, Turing Machines and Languages with Only Two Formation Rules". Communications of the ACM. 9 (5): 366–371. doi:10.1145/355592.365646. S2CID 10236439. Republished in Yourdon 1979, pp. 13–25
Dijkstra 1968. Dijkstra, Edsger (March 1968). "Go To Statement Considered Harmful". Communications of the ACM. 11 (3): 147–148. doi:10.1145/362929.362947. S2CID 17469809.

P′′ (English Wikipedia)

cambridge.org (Global: 209th place; English: 151st place)

doi.org (Global: 2nd place; English: 2nd place)