Hi,

Analising the expression grammar, I found these syntax rules to be
checked by the parser.

Boolean Expressions like: (AvB)^(!CvD)

Key for Syntax Rules:
a) [ ] means whatever is in the brackets is optional
b) ... means repeat the latter
c) no brackets mean compulsory syntax

Syntax Rules:
i) operand                     = [ ! ... ] identifier
ii) bracketed operand  = [ ( ...  xN ] operand [   ) ... xN  ]
iii) term                          = bracketed operand [ [ operator
----> bracketed operand ] ... ]
iv) bracketed term        = [ ! ... ] [ ( ...  xN ] term [ ) ... xN ]
v) expression               = bracketed term [ [ operator ----->
bracketed term ] ... ]

Edward