###########
Terminology
###########

So far, there is no consistent terminology for MRIO systems and parameters in
the scientific community. For pymrio, the following variable names (=
attributes of the IOSystem and Extensions) are used (the alias columns are
other names and abbreviations often found in the literature):

+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| variable name |  formal name                                 | alias variable names | alias formal names                 | description                                                                                                                     |
+===============+==============================================+======================+====================================+=================================================================================================================================+
| Z             |  transaction matrix                          | T                    | flow matrix                        | transactions matrix, inter industry flows                                                                                       |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| A             |  A matrix                                    |                      |                                    | inter-industry coefficients (direct requirements matrix)                                                                        |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| L             |  Leontief inverse                            | B                    |                                    | leontief inverse (total requirements matrix) (multi regional approach)                                                          |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| Y             |  final demand matrix                         | H, y                 |                                    | final demand matrix (sectors x region/countries and final demand categories)                                                    |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| x             |  gross output                                | q                    | industry output                    | total output, defined as column vector                                                                                          |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| F             |  factor production                           |                      | extensions, stressors              | Factors of productions: extensions plus value added block                                                                       |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| F_Y           |  factor production final demand              | yF, Fhh              |                                    | Factor inputs/emissions of the final demand, eg the emissions from housholds                                                    |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| S             |  factor production coefficients              | D                    | stressor coefficients              |                                                                                                                                 |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| S_Y           |  factor production coefficients final demand | DY, yD, Shh          |                                    | Factor inputs/emissions coefficients of the final demand, eg the emissions from housholds                                       |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| D_cba         |  consumption-based accounts                  | fp, con              | footprints, consumption footprints | footprint of consumption, further specification with  reg (per region) or  cap (per capita) possible                            |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| D_pba         |  production-based accounts                   | terr                 | territorial accoutns               | territorial or domestic accounts, further specification with reg (per region) or  cap (per capita) possible                     |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| D_imp         |  import accounts                             | imp                  |                                    | import accounts, further specification with  reg (per region) or  cap (per capita) possible                                     |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| D_exp         |  export accounts                             | exp                  |                                    | export accounts, further specification with  reg (per region) or  cap (per capita) possible                                     |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| M             |  multipliers                                 | m                    |                                    | total requirement factors                                                                                                       |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| pxp           |  iosystem products x products                | mxm                  |                                    |                                                                                                                                 |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+
| ixi           |  iosystem industries x industries            | nxn                  |                                    |                                                                                                                                 |
+---------------+----------------------------------------------+----------------------+------------------------------------+---------------------------------------------------------------------------------------------------------------------------------+