type ShortBool = Boolean attribute (Size = BitSizeOf (ShortInt));
The intrinsic ShortBool represents boolean values, but occupies the same memory space as a ShortInt. It is used when you need to define a parameter or record that conforms to some external library or system specification.
ShortBool is a GNU Pascal extension.
program ShortBoolDemo; var a: ShortBool; begin ShortInt (a) := 1; if a then WriteLn ('Ord (True) = 1') end.
Boolean (Intrinsic), Boolean, True, False, CBoolean, ByteBool, MedBool, WordBool, LongBool, LongestBool.