# PCP

## Definitions

• WordNet 3.6
• n PCP a drug used as an anesthetic by veterinarians; illicitly taken (originally in the form of powder or `dust') for its effects as a hallucinogen
• n PCP a person who helps in identifying or preventing or treating illness or disability
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## Usage

### In literature:

Because the drug blocks pain receptors, violent PCP episodes may result in self-inflicted injuries.
"What Works: Schools Without Drugs" by United States Department of Education
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### In news:

2 charged with 4.5 pounds of PCP .
Man on PCP went 100 mph in police chase, crashed.
Rodney King had alcohol, PCP , cocaine and pot in system.
Rodney King drowned with cocaine, PCP , alcohol, marijuana contributing.
Prince George's County police on Wednesday identified the officers involved in last Thursday's dramatic shootout with a suspect apparently high on PCP as Cpl.
Patient's meds in drug study doubled without PCP 's OK.
PCP Lab Discovered In Apartment Complex.
PCP stops patient's meds weeks before her death.
Council member Marion Barry's son pled guilty Wednesday to felony possession of PCP and marijuana before a DC Superior Court judge.
Marion Barry's Son Charged With Intent to Distribute PCP .
Marion Christopher Barry, the adult son of Ward 8 DC Councilmember Marion Barry, has been charged with possession with intent to distribute PCP , court records show.
PCP Found In Purse Sickens Resort Police Staff.
"If PCP's on board, we'll have to have five or six or seven security officers take the guy down," Morocco said.
Based on what you know, is this woman high on PCP.
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### In science:

From the PCP Theorem we immediately get that there cannot be a ρ-approximate algorithm for the independent set problem with ρ < 2 unless P = NP, but we can do better.
Inapproximability of Combinatorial Optimization Problems
Finally, using random walks in expander graphs as in [IZ89], it is possible to use the PCP theorem to show that, for every k(n), NP = PCP1,1/2k(n) [O(k(n) + log n), O(k(n))].
Inapproximability of Combinatorial Optimization Problems
PS94, FS95] shows that one can achieve cubic encoding length in the PCP Theorem with a moderate query complexity, or encoding length N 1+ε , where N is the size of the formula, using query complexity that depends on ε.
Inapproximability of Combinatorial Optimization Problems
The question of witness length in PCP construction is studied mostly for its connections to coding theory, but it has an interesting connection to approximability as well.
Inapproximability of Combinatorial Optimization Problems
Conversely, a (1 + o(1))-approximate algorithm for Max 3SAT running in 2o(n) time would provide some evidence that the proof length in the PCP Theorem cannot be linear.
Inapproximability of Combinatorial Optimization Problems
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