09/13 Notes
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e = epsilon

Don't use RegEx to find syntax, is bad.

Context Free Grammars
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They consist of 4 components (BNF)
 * Terminal Symbols = tokens
 * Non-terminal Symbols = syntactic variables
 * Start Symbol S = special non-terminal
 * Production RUles for the form LHS --> RHS

Grammar for a balenced-parentheses language
 * S--> (S)S
 * S--> e
    * 1 non-terminal: S
    * 2 terminals: "(" , ")"
    * Start symbol: S
    * 2 Production RUles

Shorthand
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vertical bar | used to combine multiple Productions
 * i.e. S --> aSa|T and T --> bTb|e

*Derivation* = sucessive application of Productions starting from S