Consider the following XML-like language, which we will call L. There are three XML tags in L which must be have an associated closing tag. These tags will be referred to as A tags, B tags, and C tags, and they are written as , , and . Their associated closing tags are , , and . We say that a tag Tinner can occur inside of another tag Touter if Tinner and its closing tag occur in between Touter and its closing tag. An example of this behavior might look as follows: , where a B tag appears inside of an A tag. In L, strings contain exactly one A tag. One or more B tags may occur in sequence inside of an A tag. Zero or one C tags may occur inside any B tag. An example of a string in L is given as follows: . Give a context free grammar for L..