!2 Any string is valid. Here we see how each string is interpreted as a boolean:
!|fitlibrary.specify.parser.ParserUnderTest|

|calculate|
|value||bool|Boolean|
|true||true|true|
|+||true|true|
|y||true|true|
|yes||true|true|

|calculate|
|value||bool|Boolean|
|false||false|false|
|||false|false|
|f||false|false|
|n||false|false|
|no||false|false|
|not||false|false|
|t||false|false|