DSL EXPRESSION:
$y =~ "\".."


AST:
"block" [tt:block] [nt:StatementBlock]
    "=~" [tt:op_eqtilde] [nt:BareBoolean]
        "=~" [tt:op_eqtilde] [nt:Operator]
            "$y" [tt:field_name] [nt:DirectFieldValue]
            ""\".."" [tt:string_literal] [nt:string_literal]

x=ABCDE,y="GHI"
