Editing Plankalkül (section)

===Data types===
The only primitive data type in the Plankalkül is a single [[binary digit|bit]] or [[Boolean data type|Boolean]] ({{langx|de|Ja-Nein-Werte}} – yes-no value in Zuse's terminology). It is denoted by the identifier <math>S0</math>. All the further data types are composite, and build up from primitive by means of "arrays" and "records".<ref name="Bauer-Wössner_1972"/>{{rp|page=679}}

So, a sequence of eight bits (which in modern computing could be regarded as [[byte]]) is denoted by <math>8 \times S0</math>, and Boolean matrix of size <math>m</math> by <math>n</math>&nbsp; is described by <math>m \times n \times S0</math>. There also exists a shortened notation, so one could write <math>S1 \cdot n</math> instead of <math>n \times S0</math>.<ref name="Bauer-Wössner_1972"/>{{rp|page=679}}

Type <math>S0</math> could have two possible values <math>0</math> and <math>L</math>. So 4-bit sequence could be written like L00L, but in cases where such a sequence represents a number, the programmer could use the decimal representation 9.<ref name="Bauer-Wössner_1972"/>{{rp|page=679}}

Record of two components <math>\sigma</math> and <math>\tau</math> is written as <math>(\sigma, \tau)</math>.<ref name="Bauer-Wössner_1972"/>{{rp|page=679}}

Type ({{langx|de|Art}}) in Plankalkül consists of 3 elements: structured value ({{langx|de|Struktur}}), pragmatic meaning ({{langx|de|Typ}}) and possible restriction on possible values ({{langx|de|Beschränkung}}).<ref name="Bauer-Wössner_1972"/>{{rp|page=679}} User defined types are identified by letter A with number, like <math>A1</math> – first user defined type.

====Examples====
Zuse used a lot of examples from chess theory:<ref name="Bauer-Wössner_1972"/>{{rp|page=680}}
{|cellpadding=5 style="border:1px solid #BBB; width:800px;"
|-
| <math>A1</math>
| <math>S1 \cdot 3</math>
| Coordinate of chess board (it has size 8x8 so 3 bits are just enough)
|-
| <math>A2</math>
| <math>2 \times A1</math>
| square of the board (for example L00, 00L denotes e2 in [[Algebraic notation (chess)|algebraic notation]])
|-
| <math>A3</math>
| <math>S1 \cdot 4</math>
| piece (for example, 00L0&nbsp;— white king)
|-
| <math>A4</math>
| <math>(A2, A3)</math>
| piece on a board (for example L00, 00L; 00L0&nbsp;— white king on e2)
|-
| <math>A5</math>
| <math>64 \times A3</math>
| board (pieces positions, describes which piece each of 64 squares contains)
|-
| <math>A10</math>
| <math>(A5, S0, S1 \cdot 4, A2)</math>
| game state (<math>A5</math>&nbsp;— board, <math>S0</math>&nbsp;— player to move, <math>S1 \cdot 4</math>&nbsp;— possibility of [[castling]] (2 for white and 2 for black), <math>A2</math>&nbsp;— information about cell on which ''[[en passant]]'' move is possible
|}