c:\test>junk5
Unbalanced parens '((A or B)' at c:\test\junk5.pl line 15, <DATA> line 1.
Unbalanced parens '(A) or B)' at c:\test\junk5.pl line 15, <DATA> line 2.
[[A].or.B]
[A.or.B.or.C.and.D]
[[this.OR.that].AND.other]
[A.or.[B.and.[C.or.D]].or.[E.and.F]]
[A.or.[B.or.C].or.[D.and.E]]