#### UPC Terms, definitions and symbols

For the purpose of these specifications the following definitions apply.

thread
  an instance of execution initiated by the execution environment at program startup.
object
  region of data storage in the execution environment which can represent values.
shared object
  an object allocated using a shared-qualified declarator or by a library function defined to create shared objects.

  Note: All threads may access shared objects.

private object
  any object which is not a shared object.

  Note: Each thread declares and creates its own private objects which no other thread can access.

shared array
  an array with elements that have shared qualified type.
affinity
  logical association between shared objects and threads. Each element of data storage that contains shared objects has affinity to exactly one thread.
pointer-to-shared
  a pointer whose referenced type is shared-qualified.
pointer-to-local
  a pointer whose referenced type is not shared-qualified.
access
  <execution-time action> to read or modify the value of an object by a thread.

  The file scope declaration int y; creates a separate object for each thread to access.

shared access
  an access using an expression whose type is shared-qualified.
strict shared read
  a shared read access which is determined to be strict.
strict shared write
  a shared modify access which is determined to be strict
relaxed shared read
  a shared read access which is determined to be relaxed
relaxed shared write
  a shared modify access which is determined to be relaxed
local access
  an access using an expression whose type is not shared-qualified.
collective
  a constraint placed on some language operations which requires evaluation of such operations to be matched across all threads. The behavior of collective operations is undefined unless all threads execute the same sequence of collective operations.
single-valued
  an operand to a collective operation, which has the same value on every thread. The behavior of the operation is otherwise undefined.
phase
  an unsigned integer value associated with a pointer-to-shared which indicates the element-offset within an affinity block; used in pointer-to-shared arithmetic to determine affinity boundaries

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