> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Basic concepts

> Core FlexiLayout language concepts: lexical conventions, reserved keywords, function-call operators, statements, name scope, variables, and coordinates.

<CardGroup cols={2}>
  <Card title="Lexical conventions" icon="spell-check" href="/flexi-capture/fls/language/conventions">
    Learn identifier syntax, punctuation, operator precedence, and comments.
  </Card>

  <Card title="Reserved keywords" icon="key" href="/flexi-capture/fls/language/r-keywords">
    See keywords that cannot be used as names.
  </Card>

  <Card title="Function-call operators" icon="code" href="/flexi-capture/fls/language/function-call">
    Pass parameters using parentheses or the colon operator.
  </Card>

  <Card title="Statements" icon="code" href="/flexi-capture/fls/language/statements">
    Write compound blocks, conditional branches, and for loops.
  </Card>

  <Card title="Name scope" icon="brackets-curly" href="/flexi-capture/fls/language/name-scope">
    Understand where variables, constants, and hypotheses are accessible.
  </Card>

  <Card title="User defined properties" icon="list" href="/flexi-capture/fls/language/element-fields">
    Declare typed variables to share hypothesis values between elements.
  </Card>

  <Card title="Variables" icon="code" href="/flexi-capture/fls/language/variables">
    Declare and initialize variables by type or with Let.
  </Card>

  <Card title="Coordinates and units of measurement" icon="ruler" href="/flexi-capture/fls/language/coordinates">
    Use global and local coordinates with distance units.
  </Card>
</CardGroup>