anchor.diff:  --------------------------------------------------
   *Input*:
   
  -<1> string expression
  -<2> string expression
  -<3> integer expression; optional
  -
  -*Output*: integer
  -
  -*Description*: Returns the starting position of the first occurrence of `pattern` within `source`. The optional `start` specifies the character position to start the search with. The first character position in `source` is indicated by the value 1. Not specifying `start` or specifying it as `null`, any negative value, 0 or 1, starts the search at the first character position. If `pattern` is not found within `source`, the value 0 is returned.
  +<1> string expression.  If `null`, the function returns `null`.
  +<2> string expression.  If `null`, the function returns `null`.
  +<3> integer expression; optional. If `null`, `0`, `1`, negative, or not
  +specified, the search starts at the first character position.
  +
  +*Output*: integer
  +
  +*Description*: Returns the starting position of the first occurrence of
  +`pattern` within `source`. The optional `start` specifies the character position
  +to start the search with. If the `pattern` is not found within `source`, the
  +function returns `0`.
   
   [source, sql]
   --------------------------------------------------
  
positive.code: --------------------------------------------------
  *Input*:
  
  <1> integer expression. If `null` or negative, the function returns `null`.
  
  *Output*: string
  
  *Description*: Returns the character that has the ASCII code value specified by the numeric input. The value should be between 0 and 255; otherwise, the return value is data source–dependent.
  
  [source, sql]
  --------------------------------------------------
  
negative.code: --------------------------------------------------
  *Input*:
  
  <1> string expression. Treats `null` as an empty string.
  <2> string expression. Treats `null` as an empty string.
  
  *Output*: string
  
  *Description*: Returns a character string that is the result of concatenating `string_exp1` to `string_exp2`.
  
  [source, sql]
  --------------------------------------------------
  