Symbols

intro
prev: Languages Are Defined By A Grammar

To recognize if what we are looking at is a language, it needs to be composed of parts. That is things which we can see over and over again and they always are accepted as being the same. We call those parts symbols.

Symbols appear at many levels. As you read this text, you might note that it consists of a series of "pages", each page discussing a specific topic. Within those pages are "paragraphs", and within paragraphs are "sentences", and within sentences are "words", and finally within words "letters". These are symbols because we can name them and distinguish them. Every time you see a letter, you recognize it as such. Same thing for a word, sentence, paragraph, or page. That is what makes those things symbols (and not doodles).

So, part of having a language that we can recognize is the we must be able to turn it into symbols. Parts that we can clearly and consistently identify.

The fact that you can identify this text as containing letter, words, sentences, and so forth, means that this text is composed of symbols.

Thus, in our building up of what a language is, we can see that the rules of a formal grammar are going to allow us to take a text and recognize it by dividing the text up into symbols.

next: Symbols, Tokens, and Terminals