To: J3                                                     J3/19-178
From:    Jon Steidel, John Reid
Subject: Problematic description of TEAM_NUMBER=
Date: 2019-July-15


1. Introduction

There are a handful of places in F2018 where we allow a TEAM_NUMBER.
We believe the intent was to allow the executing image to reference
information about a sibling of the current team, and to reference or
define coarrays on an image of a sibling of the current team.

The description of TEAM_NUMBER says TEAM_NUMBER "shall identify the
initial team or a team whose parent is the same as that of the current
team." This wording seems incorrect.

The definition of team number, and the description of the result of
the TEAM_NUMBER intrinsic are similarly flawed, using the words
"identifies the team within its parent team".


2. Interpretation Request

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NUMBER: F18/xxx
TITLE: Problematic description of TEAM_NUMBER=
KEYWORDS: TEAM_NUMBER, team number
DEFECT TYPE: Erratum
STATUS: Submitted

QUESTION:

The description of the TEAM_NUMBER argument to NUM_IMAGES and
IMAGE_INDEX states "It shall identify the initial team or a team whose
parent is the same as that of the current team."

The definition of team number, and the description of the result of
the TEAM_NUMBER intrinsic also seems incorrect. They say the team
number identifies the team in the parent team.  The team number
actually identifies a team in the set of teams described by a team
variable defined by the execution of a FORM TEAM statement.

A parent team can execute more than one FORM TEAM statement, creating
two or more sets of subteams described by different variables of type
TEAM_TYPE. Each subteam created by each FORM TEAM statement has the
same parent team. Team numbers are not unique across the FORM TEAM
statements a parent team executes.

Is the intent that TEAM_NUMBER should identify only a team created by
the same execution of the FORM TEAM statement that created the current
team?


ANSWER:

Yes.

Edits are provided to correct the description of the TEAM_NUMBER
argument to NUM_IMAGES and IMAGE_INDEX and the result of the
TEAM_NUMBER intrinsic function.  Additional edits clarify
the intent of the TEAM_NUMBER specifier for image selectors, and
fix the definition of team number.

EDITS to 18-007r1:

Define sibling team and use the term where repairs are needed.

[20:27+] Terms and definitions:
  Insert after the definition of "parent team"
  "3.145.3+
   sibling team
   a team created by the execution of the FORM TEAM statement
   that created the team (11.6.9)"

[20:30] 3.145.4 team number
  change "parent team"
  to     "set of siblings (5.3.4)"

  making the definition read
  "-1 which identifies the initial team, or a positive integer that
   identifies a team within its set of siblings (5.3.4)"

[36:23] 5.3.4 Program execution, para 2, final sentence
  replace "parent team, each"
  with "set of siblings, each such" and highlight "team number"

  to make the whole sentence read
  "Within its set of siblings, each such team is identified by its
   team_number; this is the integer value that was specified in the
   FORM TEAM statement."

[131:18-19] In 9.6 Image selectors, p3 second sentence

  replace "one of the teams that were formed by execution of the
           FORM TEAM statement for"
  with "a sibling team of"

  making the whole sentence read

  "If a TEAM_NUMBER= specifier appears in an image-selector and the
   current team is not the initial team, the value of scalar-int-
   expr shall be equal to the value of a team number for a sibling
   team of the current team, and the team of the image selector is
   that team; the object shall be an established coarray in an
   ancestor team of the current team, or an associating entity of the
   CHANGE TEAM construct."

[204:35] In 11.6.9 FORM TEAM statement, sentence 1
  after "new teams"
  insert "that are siblings of each other and"

  making the whole sentence read
  "The FORM TEAM statement creates new teams that are siblings of
   each other and whose parent team is the current team."

[380:12-13] In 16.9.97 IMAGE_INDEX, p3 TEAM_NUMBER
  replace "team whose parent is the same as that"
  with    "sibling team"

  making the whole sentence read
  "It shall identify the initial team or a sibling team of the current
   team."

[401:24-25] In 16.9.145 NUM_IMAGES, para 3, TEAM_NUMBER
  replace "team whose parent is the same as that"
  with    "sibling team"

  making the whole sentence read
  "It shall identify the initial team or a sibling team of the current
   team."

[421:9]16.9.189 TEAM_NUMBER([TEAM]), para 5,
  change "parent team"
  to "set of siblings"

  making the whole sentence read
   "The result has the value -1 if the specified team is the initial
    team; otherwise, the result value is equal to the positive integer
    that identifies the specified team within its set of siblings."

SUBMITTED BY: Jon Steidel and John Reid

HISTORY: 19-xxx   m219  Submitted


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