Context Free Grammar
S → SS
S → (S)
S → ()
S → key KEY
KEY → operator OPERATOR
OPERATOR → value VALUE
OPERATOR → value
VALUE → value VALUE
VALUE → value
VALUE → and AND
VALUE → or OR
AND → S
OR → S
S → SS
S → (S)
S → ()
S → key KEY
KEY → operator OPERATOR
OPERATOR → value VALUE
OPERATOR → value
VALUE → value VALUE
VALUE → value
VALUE → and AND
VALUE → or OR
AND → S
OR → S