### PR

PR, P.R., Pr, pr, or Pr. may refer to:

### PR (complexity)

PR is the complexity class of all primitive recursive functions – or, equivalently, the set of all formal languages that can be decided by such a function. This includes addition, multiplication, exponentiation, tetration, etc.

The Ackermann function is an example of a function that is not primitive recursive, showing that PR is strictly contained in R (Cooper 2004:88).

On the other hand, we can "enumerate" any recursively enumerable set (see also its complexity class RE) by a primitive-recursive function in the following sense: given an input (M, k), where M is a Turing machine and k is an integer, if M halts within k steps then output M; otherwise output nothing. Then the union of the outputs, over all possible inputs (M, k), is exactly the set of M that halt.

PR strictly contains ELEMENTARY.

### Pr (hieroglyph)

Pr is the hieroglyph for 'house', the floor-plan of a walled building with an open doorway. While its original pronunciation is not known with certainty, modern Egyptology assigns it the value of per, but purely on the basis of a convention specific to the discipline. However, the Ancient Greek rendering of the title pr-`3 as suggests the reconstruction of the historical ( Late Egyptian) pronunciation as *par, see Pharaoh#History of the Pharaoh title.

Pr combined with an associated "personal name", god, or location becomes the "House of .... ." An example for pharaoh Setnakhte is the city of: Pr-Atum, (city of Pithom). Pr and Ankh-(Life) is a "combination hieroglyph" and is the "word" for House of Life. The House of Life is a library for papyrus books-(scrolls), as well as a possible scriptorium.

The shape of Pr in beginning dynasties had variations in the shape of a square, with the opening. See Garrett Reference for tomb of Official Ti.

### Pr (Unix)

pr is used to paginate or columnate files for printing.

It is a required program in a POSIX-compliant environment and has been implemented by GNU as part of the GNU Core Utilities.

### PR

also p.r.; 1942, abbreviation of public relations (see public).

#### Usage examples of "pr".

Parati, e de Parati, como se percebe, estamos agora indo pra Ilhabela.

Siccio, quel fedelissimo ed amoroso servo che lo aveva raccolto bambino, salvato e nutrito con tanto affetto, era morto ed avea, pria di morire, trasmesso al cardinale F.

By the time Prest returned, Gils was fast asleep on my pallet, oblivious to the world around him.

The Council was struggling to prevent the PRA from becoming a political group with sufficient power to win a majority in the Council and declare war on Nidus, and to date it had managed the feat.

I dok se sve drugo vrtelo oko njega i bez reda i bez smisla i zbrkano, te njegove misli na oca nalazile su ga na obroncima brda, pred vidnim, proletnjim predelima, kao i ovde nad gradskim krovovima, pa su sve dovodile u red, rasporedile, smirile.

Deu-me as terras, gado, cavalos e depositou no banco uma boa quantia em dinheiro pra eu comprar a casa e tocar a fazenda.

Parati, e de Parati, como se percebe, estamos agora indo pra Ilhabela.

Ist atutese of pra I eaf as so didettummes anage oughis Wkhe dnelwrtmis, i ,,ht w andofangsmas tl.

And we can handle special trips for artists to go to their countries on special commission, accompanied by PRs to run beauty contests to select Miss Country Name with the grand prize of training and employment at the Gracious Palms.

Nodding at Pra, Abdee ordered, 'Bring this black son-of-a-bitch up on deck.

As Milos invoked Jerico pri ority, Angus' brain seemed to shut down: zone implants and programming controlled every neural flicker and muscular contraction while his datacore registered Milos' orders and compared them to its prewritten exigencies.